The Treaty of Guadalupe Hidalgo in 1848 transferred 55% of Mexican territory to the U.S., and ignited a fierce debate over slavery in these new lands.

Learn about Manifest Destiny, the 19th-century belief that the United States was meant to expand across North America. This video covers the history behind the idea, key events like the Louisiana Purchase, the Oregon Trail, and the...

This video looks at the documents conceived in a period when the civil rights of women and Native Americans were in question, and slavery was driving a wedge between slaveholders and abolitionists. Educators from noted American...