Use maps and geographic tools to explain how natural resources and movement shaped American expansion

Learning goal: Use modern and historical maps and other geographic tools to analyze how historic events were shaped by geography; explain how the availability of natural resources contributed to the geographic and economic expansion of the United States, sometimes with unintended environmental consequences; and explain how the movement of people, products and ideas resulted in new patterns of settlement and land use that influenced the nation's political and economic development.

Geographic tools and what each can answer. The standard's phrase "modern and historical maps" covers two kinds of map, and this lesson keeps them apart. A contemporary map was made during the period you are studying; it records what its maker knew, claimed or wanted to show. A modern map of the period, which historical atlases also call a historical map, is a reconstruction made later from many sources and can show things no one at the time could see, such as the whole route of a canal system or the spread of population by county. Other geographic tools include the survey grid, the elevation profile, the census table and the transportation network diagram. Each answers a different question. A contemporary map answers "what did people then believe the land looked like?"; a modern thematic map answers "what pattern does later research reconstruct?"; a profile answers "how steep was the route?" Both kinds of map must be checked the same way: who made it, when, from what sources and for what purpose, and both can be wrong. Note the difference between the date a map was made and the period it shows. Choosing the tool is the first step of analysis, and naming which tool you used is part of the answer.

How geography shaped historic events: two examples. First, the Ohio River. It flows west and south to the Mississippi, so before canals and railroads an Ohio farmer's grain went downstream to New Orleans, not east over the mountains. That fact explains why Jefferson wanted New Orleans in 1803 and why the Louisiana Purchase mattered to people in Ohio. Second, the Mississippi in the Civil War. A modern campaign map shows why Vicksburg mattered: it sat on high bluffs at a bend, commanding the river, so its capture on July 4, 1863, followed by Port Hudson's surrender on July 9, gave the Union the river and split the Confederacy. The event was shaped by the location.

Natural resources and expansion. Ohio's own resources illustrate the national pattern. Rivers gave transportation and water power. Forests supplied timber for houses, fences, boats and charcoal. Iron ore in the Hanging Rock region along the Ohio River supported iron blast furnaces from 1826 onward, and coal in the Hocking Valley of southeastern Ohio fed the coal-fired industry and railroads that came later. Fertile glacial soils in the north and west of the state supported grain and livestock. Because the state's rivers did not connect Lake Erie to the Ohio River, Ohio built canals: the Ohio and Erie from Cleveland to Portsmouth, completed in 1832, and the Miami and Erie from Cincinnati to Toledo, completed in 1845. The canals turned resources that were available but stranded into resources that could reach markets. Nationally, the same logic drove the gold rush after the discovery at Sutter's Mill in California on January 24, 1848, the settlement of the Great Plains after the Homestead Act of 1862 offered 160 acres to settlers who farmed it, and the transcontinental railroad completed at Promontory Summit, Utah, on May 10, 1869.

Unintended environmental consequences. Using a resource changed the land in ways the users did not plan. Ohio was almost entirely forested at statehood in 1803; clearing for farms, fuel and charcoal removed most of that forest during the 1800s, and the cleared slopes eroded into the streams. Canal reservoirs flooded valleys and altered drainage. In California, hydraulic mining, which used high-pressure water to wash hillsides into sluices, sent so much sediment into rivers that farms downstream were buried by mud and floods. On the Plains, the bison herds that Native nations depended on were destroyed within a few years in the 1870s by commercial hunting made possible by the railroads. The word "unintended" is doing careful work: it means outside the user's stated aim, not necessarily unforeseen. Miners intended to find gold and farmers intended to clear fields; the silted rivers and eroded hills lay outside those aims. Some such results were foreseeable and tolerated, some were noticed only afterwards, and some, like flooding a valley for a canal reservoir, were planned actions whose wider effects were not. Say which kind you are describing.

Movement of people, products and ideas. People moved west along rivers, roads and canals, and immigrants arrived from Ireland, especially during the famine of 1845–1852, and from the German states after 1848, many settling in cities such as Cincinnati. Products moved east and west along the same routes. Ideas moved too: the telegraph, demonstrated by Samuel Morse in 1844, carried news in minutes; newspapers, religious revivals and reform movements spread along the transportation network. Each movement produced a new pattern of settlement and land use.

One developed example of an idea moving: New England settlers brought to Connecticut's Western Reserve, in northeastern Ohio, the idea that the town is the unit of settlement, with a central green, a church and a school. Cleveland was laid out around a public square in 1796 by Moses Cleaveland's survey party; Hudson was founded in 1799 and became the seat of Western Reserve College in 1826. The pattern on the land, compact villages around greens with town-supported schools, followed the idea; political development followed the pattern: the Reserve became one of the strongest anti-slavery districts in the country, represented in Congress by Joshua Giddings from 1838 to 1859. That last link, from settlement culture to politics, is an interpretation historians make from the voting and church records, and should be labeled as one.

New patterns of settlement and land use. The clearest example is the survey grid. The Land Ordinance of 1785 laid out the land north of the Ohio River in townships six miles square, each divided into thirty-six sections of one square mile, or 640 acres, with section sixteen reserved to support schools. The first survey, the Seven Ranges, began in eastern Ohio. Across most of Ohio a modern map of roads and fields still shows a grid, because the pattern of land sales set the pattern of farms and roads. Ohio was not surveyed under one system, though: the Seven Ranges and the later Congress Lands used the 1785 six-mile township, the Connecticut Western Reserve used townships five miles square, and the Virginia Military District between the Scioto and Little Miami rivers, set aside for Virginia's veterans, was surveyed by metes and bounds, with irregular parcels following streams and ridges much as in Kentucky across the river. So a modern map lets you read the political decisions of the 1780s and 1790s off the land, but only once you have identified which survey district you are looking at. Canal towns, railroad towns and mining towns are further patterns: each resource or route produced a characteristic settlement shape.

How those patterns influenced political and economic development. Settlement patterns became states: the Northwest Ordinance of 1787 provided that territories would become states equal to the original ones once population thresholds were met, and Ohio did so in 1803. Land use became wealth and votes: grain and pork from the Ohio Valley made Cincinnati a major city by the 1840s, and each new state added senators and representatives to the sectional balance discussed in the previous lessons. The economic development that geography made possible therefore fed straight back into the political disputes over slavery in new territories.

A worked model with the grid. Suppose a settler in 1850 buys the northeast quarter of section 20 in a township. A section is 640 acres, so a quarter-section is 160 acres, which is also the amount later offered under the Homestead Act. If the settler sells the east half of that quarter, the buyer receives 80 acres, and the boundary runs due north-south because the grid is aligned to the compass. Now read the political consequence: a modern county map shows roads every mile on section lines, which means the road pattern, the land reserved to support schools in section sixteen and the farm sizes were all set by a national law before the parcels were sold to settlers, on land that Ohio's American Indian nations had lived on and had been made to cede.

Misconception. Students often assume a resource "causes" growth by existing. Coal in the Hocking Valley existed for millions of years before it mattered. A resource contributes to expansion only when a route, a market and a technology make it usable, which is why the map of canals and railroads explains the timing of growth better than the map of resources alone.

Worked canal estimate (hypothetical numbers): Suppose a canal boat moves 3 miles per hour for 10 hours a day, so 30 miles a day. The Ohio and Erie Canal runs about 308 miles, so a full trip takes about 308 ÷ 30 ≈ 10.3 days, roughly ten to eleven days. Suppose wagon freight costs 30 cents per ton-mile and canal freight 3 cents per ton-mile; moving one ton 100 miles costs 30 dollars by wagon and 3 dollars by canal, a tenfold difference. The speeds and rates are assumed for the exercise, not measured; the conclusion that canals made bulky goods worth shipping does not depend on the exact figures.

Worked tool choice: Question: why did the Union want Vicksburg? A contemporary newspaper map from 1863 shows what readers were told; a modern elevation and river map shows the bluffs and the bend that made the position command the river; a modern campaign map shows Grant's approach from the south and east. The elevation map answers the "why" best, the contemporary map answers "what did people know," and combining them gives the analysis the standard asks for.

Worked map comparison (a described pair, not reproduced here): Suppose a student has two maps of Ohio: a printed map dated 1827, published when only the first sections of the Ohio and Erie Canal were open, showing the planned canal routes, the counties then organized and a scale bar in miles; and a modern historical-atlas map compiled from state records, showing the canals as completed in 1832 and 1845 and county populations from the 1850 census. Compare in four steps. Date: made in 1827, against compiled recently to show 1832 to 1850. Maker and purpose: a commercial publisher selling to settlers, against historians summarizing records. Legend and scale: read what each key marks, then use each scale bar to measure Cleveland to Portsmouth and check the two against each other. Question each can answer: the 1827 map shows what a buyer of land then expected the canal to do; the modern map shows where towns actually grew along the finished line. The conclusion is limited to what the pair supports, expectation in 1827 and outcome by 1850, and the same four steps apply to any dated historical map and modern map used in the supported practice.

Worked land-use reading: A township is 6 miles by 6 miles, or 36 square miles, so 36 sections of 640 acres each, or 23,040 acres in all. Section 16 (640 acres) was reserved to support schools, so a simplified model leaves 35 sections, or 22,400 acres, for sale; the 1785 ordinance in fact also held back sections 8, 11, 26 and 29 for later sale by the United States, leaving 31 sections, or 19,840 acres, on first offer. Label which model you are using. If a modern map shows roads at one-mile intervals aligned north-south and east-west, the area was surveyed under a rectangular system, in Ohio most likely the 1785 township (the Western Reserve's five-mile townships give a similar but not identical grid); if roads follow streams and ridges, it was likely surveyed by metes and bounds, as in the Virginia Military District. A straight road alone does not date a survey; check the survey district on a map of Ohio's land subdivisions before drawing the conclusion.

Supported map analysis: Using a modern map of Ohio, mark the Ohio River, Lake Erie, the Ohio and Erie Canal (Cleveland to Portsmouth, 1832), the Miami and Erie Canal (Cincinnati to Toledo, 1845), the Hocking Valley coal field and the Hanging Rock iron region. Then write three sentences: one that a contemporary map of 1830 could support, one that only the modern map can support, and one about an unintended environmental consequence with the resource that caused it.

Independent performance: Choose one historic event between 1803 and 1877 (for example, the Louisiana Purchase, the Erie Canal, the gold rush, Vicksburg or the transcontinental railroad). Write an analysis that uses at least two different geographic tools, names them, and explains how geography shaped the event. Success criteria: each tool is identified as contemporary (made at the time) or modern and used for a question it can answer; one natural resource is named with the route or technology that made it usable; one unintended environmental consequence is described with evidence; one new settlement or land-use pattern is traced to a movement of people, products or ideas; and the last paragraph states how that pattern influenced political or economic development.