ss-2026:8:17ss-2026:8:13
ss-2026:8:17 Push and pull factors impacted the expansion of the United States environmentally, economically, politically, and socially.
ss-2026:8:13 The United States expanded the frontier westward by adding territory through armed conflict, treaties, and land purchases. Westward expansion and the concept of Manifest Destiny increased the United States’ boundaries and population while forcibly removing American Indian nations from native lands.
Learning goal: Explain how push and pull factors impacted the expansion of the United States environmentally, economically, politically and socially, and how westward expansion and the idea of Manifest Destiny increased the nation's boundaries and population while American Indian nations were forcibly removed from their native lands. This lesson teaches Ohio's 2026 social studies standards for Grade 8, published in July 2026. The Ohio Department of Education and Workforce anticipates that districts will begin implementing the 2026 standards in the 2027-28 school year.
Push and pull. Geographers explain migration with two kinds of factors. Push factors are conditions that drive people away from where they live: poverty, crop failure, lack of land, war, persecution, disaster. Pull factors are conditions that attract people to a new place: available land, jobs, gold, freedom of religion, family already there. Most moves combine both. A family leaves because something pushes and goes to a particular place because something pulls. The push-pull model works best for migration in which people choose to leave and choose where to go. Force, persecution and expulsion can be described as push factors, but for forced migration — the removal of American Indian nations or the sale of enslaved people from Virginia to Mississippi — the model has limits: the people moved did not choose to leave or choose their destination, so calling the destination a "pull" would misrepresent what happened. The decisions and power of others explain it.
Pushes and pulls in the United States, 1790–1860.
- Within the country. In the East, farm families faced worn-out soil, high land prices and farms too small to divide among children (push). West of the Appalachians, public land sold at low government prices, and fertile soil in the Ohio Valley and later the prairies (pull). Canals and railroads made the move cheaper.
- From Europe. In Ireland, potato blight caused the Great Famine of 1845 to 1852, during which about a million people died and more than a million emigrated (push); many came to American cities for work on docks, canals and railroads (pull). In the German states, poor harvests and the failure of the revolutions of 1848 pushed many to leave; farmland in the Midwest pulled them, and many settled in Ohio cities such as Cincinnati.
- Religious movement. Members of the Church of Jesus Christ of Latter-day Saints, driven out of Missouri and then Illinois by violence (push), moved west in 1846–1847 to the Great Salt Lake valley, then outside the United States, where they could practice their faith (pull).
- Gold. The discovery of gold in California in 1848 pulled hundreds of thousands of people to California in 1849 and the decade that followed, from the eastern states, Latin America, Europe and China. California became a state in 1850.
Manifest Destiny. In 1845 the journalist John O'Sullivan wrote that it was the nation's "manifest destiny" to spread across the continent. The phrase named a belief, held by many Americans, that expansion was natural and justified. It worked as a pull on public opinion: it encouraged settlers and supported politicians who wanted more territory. It was a belief, not a fact, and it was rejected by American Indian nations, by Mexico and by many Americans who opposed the war with Mexico.
How the boundaries grew. The United States added territory through land purchases (Louisiana, 1803; the Gadsden Purchase, 1853), treaties (Florida by the Adams–Onís Treaty, 1819; the Oregon boundary with Britain, 1846) and armed conflict (the Mexican–American War, 1846–1848, which ended with the Treaty of Guadalupe Hidalgo and the Mexican Cession). Texas was annexed in 1845.
How the population grew. The population grew mainly through natural increase (more births than deaths) and immigration, while added territory brought in people already living there; moving within the country redistributed people rather than adding to the national total. The census totals show the growth but not, by themselves, how much each cause added. The first census, in 1790, counted about 3.9 million people. The census counted about 9.6 million in 1820, about 23.2 million in 1850 and about 31.4 million in 1860 — eight times the 1790 figure in seventy years. Ohio alone grew from about 45,000 people in 1800 to nearly 2 million in 1850.
Forced removal. Expansion took land from people who already lived on it. The Indian Removal Act of 1830 authorized the president to negotiate the exchange of eastern lands for lands west of the Mississippi. In practice, the government used treaties signed under pressure and military force. Thousands of Cherokee people died on the forced march of 1838–1839 known as the Trail of Tears; Muscogee (Creek), Choctaw, Chickasaw and Seminole peoples were removed as well, and in Ohio the Wyandot, the last nation with a reservation in the state, were removed in 1843.
Four kinds of impact.
- Environmental: forests cleared for farms, prairie sod plowed, rivers dammed for mills, mining debris washed into California rivers, bison herds reduced as settlement and later hunting spread.
- Economic: new farms, towns and markets; canals and railroads; cheap western grain feeding eastern cities.
- Political: new territories and states; fierce debate over whether slavery could spread into new lands, which helped lead to the Civil War.
- Social: new, diverse communities of immigrants and migrants; nativism against Irish Catholic immigrants; the destruction and displacement of American Indian communities.
The misconception. Students often describe the West as "empty land" that pulled settlers. The land was home to American Indian nations and, in the Southwest, to Mexican citizens. The pull factors that drew settlers were made available by purchases, treaties, war and forced removal.
Worked example 1 — identify push and pull factors: A hypothetical Irish family, typical of many, leaves County Cork in 1847 and settles in Cincinnati. Push factors: the potato blight and famine, poverty, eviction. Pull factors: jobs on canals and in the city's growing industries, relatives already in Ohio. The student labels each factor as push or pull and names its category: economic (jobs, poverty), environmental (blight), social (family).
Worked example 2 — calculate population growth: From 1790 (about 3.9 million) to 1860 (about 31.4 million), the increase is 31.4 − 3.9 = 27.5 million people. The ratio is 31.4 ÷ 3.9 ≈ 8.05, so the 1860 population was about eight times as large as the 1790 population. From 1850 to 1860 alone, the increase was 31.4 − 23.2 = 8.2 million, more than twice the whole population of 1790. The student concludes that the nation's population grew along with its boundaries, and notes that the totals alone do not show how much came from natural increase, immigration or people in newly added territory.
Worked example 3 — trace one expansion across four impacts: The California Gold Rush. Push and pull: gold (pull); hard times in the East, Latin America, Europe and China (push). Environmental: hydraulic mining washed huge amounts of debris into rivers. Economic: San Francisco grew rapidly, and gold flowed into the national economy. Political: California's quick statehood as a free state in 1850 upset the balance between free and slave states and became part of the Compromise of 1850. Social: miners came from many nations, Chinese miners faced discriminatory taxes, and California Indian populations suffered violence and severe losses. Each impact is stated with its category.
Push-pull chart (representation task): Make a chart for four migrations from the lesson (for example eastern farm families to Ohio, Irish immigrants, German immigrants, Latter-day Saints, gold seekers). Columns: who moved; from where to where; push factors; pull factors; environmental, economic, political and social impacts. Add a separate row for one forced removal and explain why the push-pull model does not fully describe it. Then graph the census figures for 1790, 1820, 1850 and 1860 as a bar chart.
Independent performance: Write a 350–450 word explanation answering: "How did push and pull factors, Manifest Destiny and the acquisition of territory expand the United States, and at whose cost?" Success criteria: (1) you explain push and pull factors with at least two dated examples; (2) you name at least three ways the boundaries grew, including a purchase, a treaty and an armed conflict; (3) you use census figures to show population growth with correct calculations; (4) you describe at least one environmental, economic, political and social impact; (5) you explain Manifest Destiny as a belief and describe the forced removal of at least one American Indian nation.
An adult may read the prompts aloud. Answer independently with words, objects, drawings or a demonstration before opening the answer guide. Award 1 point for a correct result or claim and 1 point for a matching explanation or demonstration; where a question asks only for a result (a corrected sentence, a spelling, a count), a fully correct result earns both points, and the answer guide shows what a complete response contains. Record prompting separately. The total (two points per question) is local practice feedback, not an Ohio proficiency level.
What is the difference between a push factor and a pull factor? Give one example of each from the lesson.
A push factor drives people away from where they live, such as the Irish potato famine of 1845 to 1852. A pull factor attracts people to a new place, such as cheap public land in the Ohio Valley or gold in California in 1848.
Why does the push-pull model not fully explain the Trail of Tears?
Government force can be called a push, but the model assumes people choose where to go, and the Cherokee did not choose to leave or choose their destination; they were forcibly removed by the United States government in 1838 to 1839. Calling Indian Territory a "pull" would misrepresent the removal, so the explanation lies in government policy and force.
What was Manifest Destiny, and why is it described as a belief?
It was the idea, named by John O'Sullivan in 1845, that the United States was destined to spread across the continent. It is a belief because it was a judgment many Americans held, not a fact, and American Indian nations, Mexico and many Americans rejected it.
Name one way the United States gained territory by purchase, one by treaty and one by armed conflict.
Purchase: the Louisiana Purchase (1803) or Gadsden Purchase (1853). Treaty: Florida by the Adams-Onís Treaty (1819) or the Oregon boundary (1846). Armed conflict: the Mexican-American War (1846-1848), ending with the Mexican Cession.
Using the census figures, by how much did the population grow from 1790 to 1860, and about how many times as large was the 1860 population as the 1790 population?
It grew by about 31.4 − 3.9 = 27.5 million people, and 31.4 ÷ 3.9 ≈ 8.05, so the 1860 population was about eight times as large as the 1790 population.
Give one environmental, one economic and one political impact of expansion.
Environmental: forests cleared for farms, prairie plowed, mining debris washed into California rivers. Economic: new farms, towns and markets, canals and railroads, and cheap western grain feeding eastern cities. Political: new states and territories, and debate over whether slavery could spread into them, which helped lead to the Civil War.
Give one social impact of immigration pulled by expansion.
New, diverse communities formed, such as German communities in Cincinnati; at the same time nativism grew against Irish Catholic immigrants.
A student says, "Settlers moved west into empty land." Correct the student with evidence.
The land was home to American Indian nations and, in the Southwest, Mexican citizens. It was opened to settlers through purchases, treaties signed under pressure, war and forced removal such as the Indian Removal Act of 1830 and the Trail of Tears.