D2.Geo.9.6-8: How Changes to the Chesapeake Bay Shaped Conflict and Cooperation
In plain English: D2.Geo.9.6-8 is the C3 Framework geography indicator for grades 6-8 that asks students to evaluate how long-term environmental changes caused by people influence where conflict and cooperation happen. Students judge how much a slow change, such as worn-out oyster beds or polluted water, explains where groups fought and where they chose to work together.
Evaluate the influences of long-term human-induced environmental change on spatial patterns of conflict and cooperation.
C3 Framework for Social Studies (NCSS) · Dimension 2: Applying Disciplinary Concepts and Tools · Discipline: Geography · Human Population: Spatial Patterns and Movements · Official standard
D2.Geo.9.6-8 asks students to evaluate how long-term human-induced environmental change (a change in nature that people cause slowly, over decades or longer) influences spatial patterns of conflict and cooperation: where people clash over a place and where they agree to work together, and how those places are arranged on a map. To evaluate means to judge how strong an influence is, using evidence, and to weigh it against other causes.
This lesson uses the Chesapeake Bay. Students read an 1881 federal census report on Maryland's worn-out oyster beds and an armed clash on Virginia's Rappahannock River, the 1958 compact in which Maryland and Virginia agreed to manage the Potomac River's fish and oysters together, and a 2007 U.S. Geological Survey report on population growth, low-oxygen water and a multi-agency partnership that works with the six states in the Bay watershed. They map each event, place it on a timeline and decide how much the slow environmental change explains each pattern.
Learning Objectives
By the end of this lesson, students will be able to:
Identify a long-term environmental change caused by people, using evidence from a primary source.
Describe where conflict and cooperation happened around the Chesapeake Bay, using a map and a timeline.
Explain how a slow environmental change moved conflict to new places or pushed groups to cooperate across borders.
Evaluate how strongly environmental change influenced a pattern of conflict or cooperation, compared with another cause such as a law or a border.
Prior Knowledge Required
Students should already be comfortable with:
Explaining how people's economic choices change environments D2.Geo.4.6-8
Citing specific evidence from a primary source RH.6-8.1
"A town lake has been fished by everyone for fifty years, and the fish keep getting smaller and fewer. Where would arguments about the lake most likely break out, and what might people do to stop them?"
Take four or five answers and sort them on the board into two columns, conflict (a serious disagreement or fight between groups) and cooperation (groups working together toward a shared goal). Then ask where on a map of the lake each one would happen: at the best fishing spot, at the town line, at the dock? Point out that the slow change, fewer fish, came from people's own fishing. Today's question: how much can a slow change that people cause explain where groups fight and where they cooperate?
Direct Instruction15 minutes
Part 1: Key words. A long-term human-induced environmental change is a change in nature caused by people that builds up over decades. A spatial pattern is where something happens and how those places are arranged on a map. An oyster bed (also called an oyster bar or rock) is an area of the bottom where oysters grow in large numbers. Oystermen caught them in two ways: dredging, dragging a heavy iron frame with a bag across the bottom from a sailing vessel, and tonging, reaching down with long-handled rakes from a small boat. A watershed is all the land whose rain and rivers drain into one body of water. A compact is a formal agreement between states; Congress must consent to it.
Part 2: The place. Show Diagram 1. The Chesapeake Bay lies mostly in Maryland and Virginia, and the Potomac River forms part of the border between them. Its watershed also reaches into Delaware, Pennsylvania, New York and West Virginia.
Part 3: The question to keep asking. For every event, ask three things: What slow change did people cause? Where did conflict or cooperation happen? What else, besides the change, helps explain it?
Table 1. Facts from the four sources (Sources 1-4 are printed in Guided and Independent Practice)
Year
Fact
Source
About 1850
Oystermen thought the beds of Tangier and Pocomoke sounds could never be used up ("Thirty years ago" in an 1880 report).
Source 1
1879-80
Oysters were very scarce in Tangier and Pocomoke sounds.
Source 1
1879-80
About forty dredging boats entered Virginia's Rappahannock River; the dredgers fired on local tongmen for several weeks.
Source 2
1958
Maryland and Virginia agreed to the Potomac River Compact, creating one fisheries commission with members from both states.
Source 3
1950-2000
The Bay watershed's population grew from 8.1 million to almost 16 million.
Source 4
After 1970
Water with no oxygen in the Bay became more frequent.
Source 4
Mid-1980s to 2000
The USGS joined the Chesapeake Bay Program, a partnership of many agencies; it created the Chesapeake 2000 agreement.
Source 4
Naming the long-term change
Table 1 says the Tangier and Pocomoke beds seemed impossible to use up around 1850 but were scarce by 1879-80, after years of dredging. Is the oyster shortage a long-term human-induced environmental change?
Result: Yes. People caused it by dredging, and it built up over about thirty years. A single storm would be a sudden natural event, not a long-term human-induced change.
Reading the numbers
Source 1 says oysters "decreased at least four-fifths in Pocomoke sound and two-thirds in Tangier." At most what fraction of the oysters was left in each sound?
Result: Pocomoke: 1 - 4/5 = 1/5, so at most one fifth (20%) was left. Tangier: 1 - 2/3 = 1/3, so at most one third (about 33%) was left. Pocomoke Sound lost the larger share.
Measuring the pattern on the map
Use Diagram 1. How far is it from marker 1 (Tangier Sound) to marker 4 (the mouth of the Potomac River)?
Result: About 19 miles (18.9 miles, computed from the official map points). The worn-out beds and the river the two states later managed together lie close to each other, in the middle of the Bay where Maryland and Virginia meet.
Weighing another cause
Source 2 says Virginia had banned dredging on its natural oyster rocks and then did away with its police force before the dredgers came. Does the environmental change alone explain the Rappahannock fight?
Result: No. Scarce oysters elsewhere gave dredgers a reason to look for new beds, but the missing police made the Rappahannock an easy target. A strong evaluation names both causes and judges which mattered more, with evidence.
Guided Practice15 minutes
Read Sources 1 and 2 together. Both come from an 1881 report written for the Tenth Census of the United States. The author, Ernest Ingersoll, quotes R. H. Edmonds, who collected oyster facts in Maryland and Virginia. Words to know: exhaustless (never running out), depredation (raiding or stealing), tongmen or tongers (oystermen who use tongs), overawed (kept in line by fear).
As the best-stocked and most productive beds of Europe were quickly destroyed by unrestricted dredging, so may the hitherto seemingly exhaustless beds of the Chesapeake bay be depleted, if the present rate of dredging is continued. An illustration of this may be seen in the almost total exhaustion of the once famous beds of Tangier and Pocomoke sounds. Year after year these beds were dredged by hundreds of vessels, and even the summer-months afforded them but little rest. The result of this has been plainly seen during the past few years, and more especially during the season of 1879–'80, in the great scarcity of oysters in these sounds. Vessels having found it unprofitable to dredge in these sounds, since the oysters became so scarce, have turned their attention to other parts of the bay, and will thus give the beds a year or so of comparative rest. It is doubtful if they will ever again be as well stocked as in former years, for as soon as oysters again become plentiful, there will be a rush of all the dredging-boats in the state. Thirty years ago the depletion of these beds seemed almost impossible, and yet, at the present time, it is an admitted fact that oysters have decreased at least four-fifths in Pocomoke sound and two-thirds in Tangier. If it were possible to restrict dredging so as to give every bed an occasional year of rest, the result would prove the wisdom of such a course. Owing to the great extent of the oyster-beds in the bay, and their immense annual production, it may be some years before there is an oyster-famine, but sooner or later it is coming, unless there is a radical change in some of the present phases of the business. Properly protected and cared for, the ‘imbedded wealth’ of the Chesapeake might be increased many fold. It is a shame that the gifts so lavishly bestowed by nature upon Maryland and Virginia should receive so little practical appreciation.
Ernest Ingersoll, quoting Census special agent R. H. Edmonds, The Oyster-Industry: “Prospective destruction of the oyster-beds” (Source 1) (1881). Public domain (published 1881). Source text.
1All the boats of the police fleet are supplied with cannon and a large quantity of small-arms, and quite often there is need of the latter, as a fight with the dredgers will occasionally occur. Of late, however, these battles are becoming less frequent.
[...]
2It would be necessary for the state to maintain the police force, even if it had to be done by appropriation from the general treasury. Disband the force, and in a few weeks the bay would be a battle ground for tongers and dredgers. This was plainly demonstrated last winter, on the Rappahannock river. Virginia having abolished dredging on natural rocks, it was decided to do away with the police force. In the winter of 1879–'80 about forty dredging-boats entered the Rappahannock and began work. The native tongmen, incensed at this depredation upon their beds, undertook to drive the dredgers away. In this, however, they signally failed. The dredgers, being well supplied with rifles, opened fire upon the tongmen. For several weeks the appearance of a tongman at any time, was certain to draw forth a volley from the dredgers. The legislature being in session at the time, it was decided to supply the tongmen with a cannon, a large number of rifles, and a supply of ammunition. Before the arrival of these, however, the dredgers had left. Such is but a sample of what would be constantly occurring, if the dredgers of Maryland were not overawed by the police.
Ernest Ingersoll, quoting Census special agent R. H. Edmonds, The Oyster-Industry: the police fleet and the Rappahannock (Source 2) (1881). Public domain (published 1881). Source text.
Find the change. In Source 1, underline the words that show the beds were worn out by people, not by nature.
Find the movement. Circle the sentence that says where the dredging vessels went next. Ask: if the vessels move, what happens to the place where people might clash?
Find the conflict. In Source 2, paragraph 2, box the place, the date and the two groups. Mark marker 3 on Diagram 1.
Weigh the causes. Ask: what changed in Virginia's laws just before the fight? List it next to the environmental change. Which do students think mattered more, and why?
Notice the author's view. Edmonds argues for a police force. Ask: how might that goal shape the way he describes the dredgers?
Independent Practice15-20 minutes
Read Sources 3 and 4 and complete the organizer. Source 3 is the 1958 compact between Maryland and Virginia, printed in a 1962 federal law. Source 4 comes from a 2007 U.S. Geological Survey (USGS) report. Words to know: tidewater (the part of a river that rises and falls with the tide), riparian rights (rights of people who own land along a river), estuary (a bay where fresh river water mixes with salt sea water), hypoxia (water with too little oxygen for most animals) and anoxia (water with no oxygen).
1Whereas Maryland and Virginia are both vitally interested in conserving and improving the valuable fishery resources of the Tidewater portion of the Potomac River, and
2Whereas, certain provisions of the Compact of 1785 between Maryland and Virginia having become obsolete, Maryland and Virginia each recognizing that Maryland is the owner of the Potomac River bed and waters to the low water mark of the southern shore thereof, as laid out on the Mathews-Nelson survey of 1927, and that Virginia is the owner of the Potomac River bed and waters southerly from said low water mark as laid out, and that the citizens of Virginia have certain riparian rights along the southern shore of the river, as shown on said Mathews-Nelson survey, and, in common with the citizens of Maryland, the right of fishing in said river, Maryland and Virginia have agreed that the necessary conservation and improvement of the tidewater portion of the Potomac fishery resources can be best achieved by a Commission comprised of representatives of both Maryland and Virginia, charged with the establishment and maintenance of a program to conserve and improve these resources, and
[...]
3SECTION 1. COMMISSION CREATED.—The Potomac River Fisheries Commission, hereinafter designated as “Commission”, is hereby created.
4SEC. 2. MEMBERS.—The Commission shall consist of six members, three from Maryland and three from Virginia. [...]
[...]
5SECTION 1. OYSTER BARS.—The Commission shall make a survey of the oyster bars within its jurisdiction and may reseed and replant said oyster bars as may from time to time be necessary.
6SEC. 2. FISH AND SEAFOOD.—The Commission may by regulation prescribe the type, size and description of all species of finfish, crabs, oysters, clams and other shellfish which may be taken or caught, within its jurisdiction, the places where they may be taken or caught, and the manner of taking or catching.
Congress of the United States, Public Law 87-783 (1962), quoting the compact, Potomac River Compact of 1958: preamble and Articles I and III (Source 3) (1962). US government work (17 U.S.C. 105). Source text.
1The Chesapeake Bay, the Nation’s largest estuary, has been affected by human-population increase resulting in degraded water quality, loss of habitat, and declines in populations of biological communities. Since the mid-1980s, the USGS has been a partner of the Chesapeake Bay Program (CBP), a multi-agency partnership working to restore the Bay ecosystem. The CBP created Chesapeake 2000, an agreement that established over 100 restoration commitments to be achieved during 2000–10. [...]
[...]
2The population of the Chesapeake Bay watershed grew from 8.1 million in 1950 to almost 16 million in 2000, greatly expanding urban and suburban areas. [...]
[...]
3The USGS worked with the USEPA and the six states in the Bay watershed to establish the CBP Nontidal Water-Quality Network. Data from the network are used to document water-quality change that is related to land use, implementation of management actions, and climate variability.
[...]
4Seasonal anoxia (a lack of dissolved oxygen lasting weeks to months) probably occurred periodically during the relatively wet periods between 1600 AD and 1960 AD, and became more frequent after 1970 (fig. 10.2). These findings, together with earlier research, clearly indicate that hypoxia and anoxia were much more severe and extensive in Chesapeake Bay and its tributaries during the past four decades than at any time in the past 500–2,500 years.
U.S. Geological Survey (Scott W. Phillips, Peter R. Claggett and Debra A. Willard), Circular 1316, Synthesis of U.S. Geological Survey Science for the Chesapeake Bay Ecosystem (Source 4) (2007). US government work (17 U.S.C. 105). Source text.
Organizer. For each source, students fill in four boxes: The change people caused; Where it happened; Conflict or cooperation, and where; How strong was the influence of the change (strong, partial or weak), with one piece of evidence. Students work alone for 10 minutes, then compare with a partner and revise one box.
Closure10 minutes
Exit ticket. "Compare the Rappahannock fight in 1879-80 with the Chesapeake Bay Program. For each, write one sentence about where it happened and one sentence judging how much a long-term change caused by people explains it."
Teacher note. Source 2 describes armed fights and gunfire between two groups of oystermen (the excerpt reports shooting and weapons but no injuries or deaths). Preview it before class, tell students what it contains, and keep the focus on causes and places rather than the violence. In Source 2, "native tongmen" means local Virginia oystermen, not Native Americans. The 1881 report uses the spelling and capitalization of its time (for example, "Chesapeake bay").
Differentiation Strategies
For Struggling Students
Give a partly filled organizer with the change box completed for Sources 1 and 4.
Read Source 1 aloud in three chunks and pause after each to ask: what happened to the oysters, and who did it?
Provide the frame: "Because people ___ for many years, ___ happened at ___ (place)."
For Advanced Students
Use Diagram 2 to measure how many years passed between the first sign of change and each response, and explain why cooperation took so long.
Find which states in the Bay watershed do not touch the Bay itself and explain why they would join a cleanup partnership.
Write a short argument: did the oyster shortage lead more to conflict or to cooperation? Use at least three sources.
Assessment Guidance
What to Look For
Strong answers name a change that people caused and that built up over a long time, place each conflict or cooperation on the map, and explain the link between the two. The best answers also name a second cause (a law, a border, the end of a police force) and judge, with evidence, how much the environmental change mattered compared with it. Watch for students who treat any event as "caused by the environment" without showing the link.
02
Classroom Activities
3 Activities
1
Change, Conflict or Cooperation? Card Sort
15 minPairs
Pairs sort 10 cards about the Chesapeake Bay into three columns: Long-term change caused by people, Conflict and Cooperation. Then they draw arrows from each change card to a conflict or cooperation card it helps explain.
The 10 Cards
Hundreds of vessels dredged Tangier and Pocomoke sounds year after year.
Oysters in Pocomoke Sound fell by at least four-fifths.
Dredgers fired on tongmen on the Rappahannock River.
Maryland's police boats carried cannon because fights with dredgers sometimes broke out.
Maryland and Virginia created one Potomac River Fisheries Commission.
The commission has three members from each state.
The Bay watershed's population grew between 1950 and 2000.
Water with no oxygen became more frequent in the Bay after 1970.
The USGS worked with the USEPA and six states to check water quality.
Virginia's legislature decided to send the tongmen a cannon and rifles.
Answer Key
Change: 1, 2, 7, 8. Conflict: 3, 4, 10. Cooperation: 5, 6, 9. Sample arrows: card 1 to card 2 (dredging wore out the beds), card 2 to card 3 (a possible link: ask pairs how strong the evidence for it is), card 8 to card 9 (low-oxygen water is a problem no single state can fix alone).
Discussion
Ask: which card could go in two columns? (Card 4 shows conflict, but the police force was also the state's way of keeping order.) Which arrow is the weakest, and why? Pairs must give a reason from a source for every arrow they keep.
2
Mapping the Pattern
20 minGroups of 3
Groups build their own map of the pattern on a blank outline of the Chesapeake Bay, then describe how the places of conflict and cooperation are arranged.
Tasks
Copy markers 1-4 from Diagram 1 onto the blank map, using blue for change, red for conflict and green for cooperation.
Use the 25-mile scale bar on Diagram 1 to estimate the distance from Crisfield to Norfolk and from Baltimore to Norfolk.
Trace the Potomac River from its mouth toward Washington and label it "one commission for both states, 1958."
Write an arrow and a label pointing north off the map: "Bay watershed reaches Pennsylvania and New York."
Shade in green the waters covered by the 1958 compact (Source 3, paragraph 1), and draw a green arrow off the map toward the rest of the watershed covered by the partnership in Source 4.
Answer Key
2. Crisfield to Norfolk is about 76 miles (75.8 miles from the Census points; accept 70-80). Baltimore to Norfolk is about 165 miles (accept 155-175). 5. Shade the Potomac from its mouth toward Washington, the part that rises and falls with the tide (the "Tidewater portion"); the arrow points north and west, off the map.
Discussion
Ask: why does the cooperation in Source 4 cover a much bigger area than the 1958 compact? Let each group answer in one sentence, citing Sources 3 and 4, and compare answers across groups.
3
How Strong Was the Influence? Evidence Line
15 minWhole class, then individuals
Draw a line on the board from weak influence to strong influence. For each of four events, students place a sticky note showing how much the long-term environmental change explains it, and write one piece of evidence on the note.
The Four Events
The Rappahannock fight, winter 1879-80 (Source 2)
Maryland's armed police fleet (Source 2)
The Potomac River Compact of 1958 (Source 3)
The Chesapeake Bay Program partnership (Source 4)
What to Listen For
There is no single correct spot, and the score depends on the evidence. Strong notes name a second cause and weigh it: for event 1, Virginia's removal of its police force; for event 3, a reason in the preamble that has nothing to do with the condition of the fishery; for event 4, the report's link between population growth and degraded water.
Variation: Two-Sided Debate
Split the class. One side argues that the long-term change led mostly to conflict, the other that it led mostly to cooperation. Each side must use at least one source the other side also uses.
03
Diagrams & Visual Aids
2 diagrams
Diagram 1: Map of the Chesapeake Bay: Where Change, Conflict and Cooperation Happened
Real data. State outlines: U.S. Census Bureau 2023 cartographic boundary file (1:5,000,000). City dots: 2023 Census Gazetteer points. Markers 1-4: the official points in the U.S. Geological Survey's Geographic Names Information System (GNIS) for Tangier Sound, Pocomoke Sound and the mouths of the Rappahannock and Potomac rivers. The watershed states are those listed for the Bay watershed in the USGS Circular 1316 record. Equirectangular projection; the scale bar is true at about 38° N.
Diagram 2: Timeline of Change, Conflict and Cooperation, 1840-2010
Each event is placed to scale by year. Dates come from Sources 1-4; "About 1850" is thirty years before the 1880 report in Source 1 ("Thirty years ago"). Blue marks above the line are long-term changes; red and green marks below the line are conflict and cooperation.
04
Homework Assignment
~30 min
D2.Geo.9.6-8 Homework: The Clam Beds of Merrin Bay
Directions: Merrin Bay is an invented bay, made up for this homework, and all its data are invented. The north shore belongs to the state of Ashcombe and the south shore to the state of Tolland. The Varrow River flows into the bay from the farm country of Calloway, an inland state that does not touch the bay. Use the facts below, and Sources 1-4 from class, to answer the problems.
Clams harvested (invented data, bushels per year): North zone (Ashcombe): 1960, 48,000; 1975, 21,000; 1990, 9,000; 2005, 7,500. South zone (Tolland): 1960, 30,000; 1975, 33,000; 1990, 26,000; 2005, 12,000. Events (invented): 1978, clam boats from Ashcombe begin working the south zone. 1979, Tolland clammers block the harbor of the south zone with their boats for a week. 1992, the two states create a joint Merrin Bay Clam Board. 2001, state scientists report that soil and fertilizer washing down the Varrow River feed algae that use up oxygen near the river mouth. 2006, Ashcombe, Tolland and Calloway sign a cleanup pact.
Part 1: Find the Change and the Pattern (Problems 1-3)
By what percent did the north zone harvest fall from 1960 to 1990? Show your work, and say whether this is a long-term change.
Name two long-term environmental changes caused by people in Merrin Bay. For each, explain what makes it long-term and what makes it human-induced.
Describe the spatial pattern of the 1979 conflict: where did it happen, which groups were involved, and how does the north zone's harvest help explain why it happened there?
Part 2: Evaluate (Problems 4-6)
Explain why Calloway, which does not touch Merrin Bay, signed the 2006 pact. Compare this with one source about the Chesapeake Bay.
Name one cause of the 1979 harbor blockade other than the fall in clams. Then judge which cause mattered more and give your reason.
Write a paragraph of 5-7 sentences: "How much did long-term environmental change caused by people shape where conflict and cooperation happened around Merrin Bay?" Compare Merrin Bay with the Chesapeake Bay at least once, using a source.
Rubric
Criterion
Full Credit (2 pts)
Partial Credit (1 pt)
Identifies the Change
Correct calculation and two changes, each shown to be long-term and caused by people
Calculation or one change is missing or unexplained
Describes the Spatial Pattern
Places conflict and cooperation precisely and links each to the change
Names places without linking them to the change
Evaluates with Evidence
Weighs the change against another cause and uses a Chesapeake source correctly
Gives an opinion with little evidence or no second cause
05
Quiz: 20 Questions
Interactive, with answers
Instructions
Questions 3, 4, 5, 7 and 17 use Source 1, and questions 6, 7, 8, 17, 18 and 20 use Source 2 (both in Guided Practice). Questions 9, 10, 11, 16, 19 and 20 use Source 3, and questions 12, 13, 19 and 20 use Source 4 (both in Independent Practice). Question 14 uses Diagram 1 and question 15 uses Diagram 2. Choose the best answer, then check it.
Multiple choice: pick an option to check it. Short answer: write your answer, then reveal the model answer.
0 of 20 answered · 0 correct
Question 1 of 20 · Multiple Choice
Which of these is a long-term human-induced environmental change?
Answer: B
Runoff from farms is caused by people and builds up over decades, so it is long-term and human-induced. A hurricane (A) and an eruption (C) are natural and sudden. A bridge (D) is a human decision, not a change in the environment.
Question 2 of 20 · Multiple Choice
Which statement describes a spatial pattern of cooperation?
Answer: D
A spatial pattern is about where something happens and how far it reaches, so towns joining first on the shore and then farther inland is spatial. Choice A describes a pattern in time, not space. Choices B and C describe cost and opinion.
Question 3 of 20 · Multiple Choice
Which quotation from Source 1 best shows that people, not nature, caused the oyster shortage in Tangier and Pocomoke sounds?
Answer: C
Dredging by hundreds of vessels, year after year, is human action repeated over a long time. Choice A praises nature's gifts but says nothing about the cause of the shortage. Choice B is a prediction, and choice D describes the size of the beds.
Question 4 of 20 · Multiple Choice
Source 1 says oysters in Tangier Sound "decreased at least two-thirds." If a Tangier bed once gave 6,000 bushels a season, at most how many bushels would it give after that decrease?
Answer: D
A decrease of two-thirds leaves one third: 6,000 x 1/3 = 2,000 bushels. Choice A (4,000) is the amount lost, not the amount left. Choice C (1,200) uses Pocomoke Sound's four-fifths: 6,000 x 1/5. Choice B (3,000) treats the decrease as one half.
Question 5 of 20 · Multiple Choice
According to Source 1, what would help the oyster beds recover?
Answer: A
Source 1 says: "If it were possible to restrict dredging so as to give every bed an occasional year of rest, the result would prove the wisdom of such a course." Choice B confuses the "Thirty years ago" sentence with a remedy. Choice C misreads the mention of Europe, which is a warning, not a source of oysters. Choice D is not in the source.
Question 6 of 20 · Multiple Choice
According to Source 2, paragraph 2, how did the fight on the Rappahannock River end?
Answer: B
Source 2 says: "Before the arrival of these, however, the dredgers had left." Choice A is wrong because the cannon never arrived and the tongmen "signally failed" to drive the dredgers away. Choices C and D do not appear in the source.
Question 7 of 20 · Multiple Choice
Which conclusion about the Rappahannock fight is best supported by Sources 1 and 2 together?
Answer: B
Source 1 says dredgers moved to "other parts of the bay," and Source 2 describes forty boats entering the Rappahannock in the same season, but neither names where those boats came from. A careful evaluation treats the link as possible, not proven. Choice A claims Source 1 says more than it does. Choice C has no support, and in choice D, Source 2 says the dredgers "opened fire."
Question 8 of 20 · Multiple Choice
What does Source 2, paragraph 1, suggest about fights on the Maryland oyster beds around 1880?
Answer: C
Paragraph 1 says a fight with the dredgers "will occasionally occur" and that "these battles are becoming less frequent." Choice A is too strong: fights still happened. Choices B and D are not supported.
Question 9 of 20 · Multiple Choice
According to Source 3, paragraph 2, who owns the Potomac River bed and waters up to the low water mark of the southern shore?
Answer: C
The preamble recognizes "that Maryland is the owner of the Potomac River bed and waters to the low water mark of the southern shore." Choice A is wrong because Virginia owns only the waters south of that line. Choice D describes a common way rivers are split, but not this one.
Question 10 of 20 · Multiple Choice
Which phrase from Source 3, paragraph 2, shows that Virginians keep a shared right in the river even though Maryland owns most of it?
Answer: A
The phrase says Virginians share "the right of fishing" with Marylanders, a reason both states need a say in managing the fish. Choice B describes the old compact, choice C names the survey that set the line, and choice D describes the commission's job.
Question 11 of 20 · Multiple Choice
Which power in Source 3 links the compact most directly to the condition of the oyster beds?
Answer: A
Surveying, reseeding and replanting oyster bars (paragraph 5) is a direct response to beds that need rebuilding. Choice B only names the commission. Choices C and D describe how the compact was written and approved, not the oyster beds.
Question 12 of 20 · Multiple Choice
Source 4 says the Bay watershed's population grew from 8.1 million in 1950 to almost 16 million in 2000. About how many times larger was the 2000 population?
Answer: D
16 / 8.1 is about 1.98, so the population about doubled. Choice C (about 8 times) comes from dividing 16 by 2 instead of by 8.1. Choice A would mean only about 12 million people in 2000 (8.1 x 1.5), and choice B about 24 million (8.1 x 3).
Question 13 of 20 · Multiple Choice
According to Source 4, paragraph 4, when were hypoxia and anoxia more severe and extensive than at any time in the past 500-2,500 years?
Answer: C
Source 4 says hypoxia and anoxia "were much more severe and extensive ... during the past four decades" (the report is from 2007). Choices A and B describe earlier times when low oxygen happened only briefly or periodically. Choice D is not mentioned.
Question 14 of 20 · Multiple Choice
Use Diagram 1. Where is the 1879-80 conflict (marker 3) compared with the worn-out beds of Tangier Sound (marker 1)?
Answer: A
The haversine distance between the two official points is 36.5 miles, and marker 3 sits at the mouth of the Rappahannock River in Virginia, southwest of marker 1. Choice D gives the distance from marker 1 to marker 4, the Potomac. Choice C is about the distance from Baltimore to Norfolk.
Question 15 of 20 · Short Answer
Use Diagram 2. How many years passed between the Rappahannock fight (use 1880) and the Potomac River Compact of 1958? What does this gap suggest about how cooperation responds to a long-term change?
Model answer: 1958 - 1880 = 78 years. Cooperation came much later than the first conflict. A slow change can lead to conflict quickly, as boats compete for what is left, while a shared plan between states takes decades of laws and negotiation. Full credit: correct subtraction and a reasonable explanation of the gap.
Question 16 of 20 · Short Answer
Source 3, paragraphs 1 and 2, gives more than one reason for a new compact. Name two reasons, and judge which one is linked to environmental change.
Model answer: (1) Both states are "vitally interested in conserving and improving the valuable fishery resources" of the Potomac (paragraph 1). (2) "Certain provisions of the Compact of 1785" had become "obsolete" (paragraph 2). The first reason is linked to the condition of the fishery, a resource that needed conserving; the second is about an outdated legal agreement, not the environment. Full credit: both reasons with evidence and a clear judgment.
Question 17 of 20 · Short Answer
Describe the spatial pattern of conflict shown in Sources 1 and 2, and explain how the long-term change in the oyster beds influenced it.
Model answer: Conflict happened out on the oyster grounds, between dredgers and tongmen, and it moved. Source 1 says that after Tangier and Pocomoke sounds were worn out, dredgers "turned their attention to other parts of the bay." In the same season, about forty dredging boats entered Virginia's Rappahannock River and fired on local tongmen (Source 2). The worn-out beds likely pushed boats toward new places (neither source says where the forty boats came from), so conflict showed up where dredging boats met beds that local tongmen worked. Full credit: places, groups and the link to the change, with a quotation.
Question 18 of 20 · Short Answer
Source 2, paragraph 2, ends: "Such is but a sample of what would be constantly occurring, if the dredgers of Maryland were not overawed by the police." Is this sentence a fact or a prediction? Explain why that matters when you use Source 2 as evidence of where conflict happened.
Model answer: It is a prediction (an opinion about what would happen), not a report of events. Edmonds uses the Rappahannock fight to argue that Maryland should keep its police force. So Source 2 is good evidence that one fight happened on the Rappahannock in 1879-80, but weaker evidence for how often or where fights would happen elsewhere. Full credit: identifies a prediction and explains its limit as evidence.
Question 19 of 20 · Short Answer
Compare the area covered by cooperation in Source 3 (1958) with the area covered in Source 4 (2000s). Explain the difference using the kind of environmental change each one dealt with.
Model answer: The 1958 compact covers one river, the tidewater Potomac, where both states fish and Maryland owns the riverbed. Source 4's partnership covers the whole Bay and its watershed, working with "the six states in the Bay watershed." Oysters and fish sit in the shared river, but low-oxygen water and degraded water quality come from the growing population and land use across the watershed, so cooperation had to reach upstream states too. Full credit: describes both areas and links each to its change.
Question 20 of 20 · Short Answer
Evaluate this claim: "Around the Chesapeake Bay, long-term environmental change caused by people led to more cooperation than conflict." Agree or disagree, using evidence from at least two sources and naming one other cause.
Model answer (either side can earn full credit): Agree. The 1880s conflict was real (Source 2), but the lasting responses were cooperative: a joint commission that surveys and replants oyster bars (Source 3) and a partnership of many agencies and six states (Source 4). Another cause matters too: in 1879-80, Virginia had just done away with its police force, so the fight was not caused by the oyster shortage alone. A student who disagrees can also earn full credit, for example by arguing that the armed police fleet and the Rappahannock gunfire (Source 2) show decades of conflict before the 1958 compact, and that the compact also had a legal reason (the obsolete Compact of 1785, Source 3). Full credit: a clear position, two sources used accurately and a second cause weighed.
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Frequently Asked Questions
10 Questions
What does D2.Geo.9.6-8 mean?
D2.Geo.9.6-8 asks middle school students to judge how slow environmental changes caused by people affect where groups clash and where they work together. Students look for a change that builds up over decades, such as overfishing or water pollution, map the conflicts and agreements connected to it, and decide how much the change explains them compared with other causes.
What counts as long-term human-induced environmental change?
It is a change in nature that people cause and that builds up over many years. Examples are the slow loss of fish or shellfish from overharvesting, soil washing off farmland, the draining of wetlands or rising pollution in a river. A single flood or storm is not long-term and is usually not caused by people.
What is a spatial pattern of conflict or cooperation?
It is where conflicts or agreements happen and how those places are arranged on a map. Students ask questions such as: Do conflicts cluster along a border? Do they move as a resource runs out? Does cooperation cover one river or a whole watershed?
Why does the standard say "evaluate" instead of "explain"?
Evaluating means judging how strong an influence is, not just describing it. Students weigh the environmental change against other causes, such as laws, borders or police, and decide with evidence whether the change was a strong, partial or weak influence.
Is D2.Geo.9.6-8 taught in geography or in history class?
It is a geography indicator, but it fits both. It is usually taught in grades 6-8 world or U.S. geography, and it works well in U.S. history units that use primary sources about a place over time.
Why use the Chesapeake Bay for this lesson?
The Bay has a long, well-documented record of change, conflict and cooperation in federal sources. An 1881 census report describes worn-out oyster beds and armed clashes, a 1962 federal law prints the 1958 compact between Maryland and Virginia, and a 2007 U.S. Geological Survey report describes a partnership across the watershed.
Are the 1880s sources reliable?
They are useful but need care. The report was written for the federal census by people who collected facts on the spot, which makes it valuable. Its author also argues for a state police force, so students should separate the events it reports from its predictions and opinions.
How does this standard connect to D2.Geo.9.9-12?
The high school indicator D2.Geo.9.9-12 moves from human-caused change to long-term climate variability, and asks how it influences migration, settlement, resource use and land use from local to global scales. The middle school skill of linking a slow change to a pattern on the map prepares students for it.
What mistakes do students make with D2.Geo.9.6-8?
Many students treat every event as caused by the environment, without showing the link. Others describe a change in time but not in space. Ask students to name the place, the change, the link and one other cause every time.
How can I assess D2.Geo.9.6-8 beyond a quiz?
Use a mapping task and a written evaluation. Students map where a change, a conflict and a cooperative agreement happened, then write a paragraph judging how much the change explains each one. The rubric scores the evidence and the reasoning, not the side a student takes.
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Related Standards
6 standards
These standards connect to D2.Geo.9.6-8: prerequisites to review first, parallel standards at the same level, and next steps that build on it.
Before this lesson
D2.Geo.4.6-8Prerequisite
Explain how cultural patterns and economic decisions influence environments and lives
Explain multiple causes and effects of events and developments in the past
Lesson coming soon
After this lesson
D2.Geo.9.9-12Next step
Evaluate how long-term climate variability influences migration, settlement and land use
Lesson coming soon
D2.Geo.11.9-12Extends to
Evaluate how globalization and scarce resources drive conflict and cooperation
Lesson coming soon
Standard text: National Council for the Social Studies (NCSS), The College, Career, and Civic Life (C3) Framework for Social Studies State Standards: Guidance for Enhancing the Rigor of K-12 Civics, Economics, Geography, and History (Silver Spring, MD: NCSS, 2013). NCSS was not involved in the production of this lesson and does not endorse it.
