Chapter 1
United States History, Government, and Citizenship
Course: Elementary Education Multiple Subjects 7001
Subject: Elementary Education Social Studies Subtest 7004
Chapter: United States History Government And Citizenship
1. Westward Expansion (early 1800s to 1890)
Manifest Destiny and Territorial Growth
Westward expansion was fueled by the ideology of Manifest Destiny—the belief that the United States had a divine right and obligation to expand across the North American continent. This belief guided policy decisions and justified the acquisition of territory, often at the expense of Native American populations and foreign governments.
Key territorial milestones
- The Louisiana Purchase (1803) doubled the size of the U.S. and opened the interior to exploration and settlement.
- The annexation of Texas (1845) led to the Mexican-American War, culminating in the Treaty of Guadalupe Hidalgo (1848), through which the U.S. gained present-day California, Nevada, Utah, and parts of several other states.
- The Oregon Treaty (1846) with Britain settled boundary disputes in the Pacific Northwest.
- The Gadsden Purchase (1854) completed the southern U.S. border, facilitating railroad development.