Mexican American War (APUSH)

Manifest Destiny

A notion held by nineteenth-century Americans that the United States was destined to rule the continent, from the Atlantic to the Pacific. Democrats used it in the 1840s to justify the war with Mexico and it was also used to divide half of the Oregon territory with Great Britain.

Texas Annexation (1845)

Texas declared independence from Mexico in 1836 and became the Republic of Texas. After a decade, Texas was annexed by the United States in 1845, which led to the Mexican-American War

Treaty of Guadalupe Hidalgo

This treaty ended the Mexican-American War in favor of the United States. The war began over a territorial dispute involving Texas

Mexican American War (1846-1848)

Conflict between the United States and Mexico over territory, including Texas. Ended with the Treaty of Guadalupe Hidalgo, granting the U.S. significant land.

President James K. Polk

President James K. Polk: 11th U.S. President (1845-1849), expanded U.S. territory through the Mexican-American War, and supported Manifest Destiny.

Mexican American War effect on minorities

Mexican-American War increased US territory, but marginalized Mexican, Native American, and African American communities. Led to debates on slavery expansion.

Nueces River

Nueces River: A river in Texas that flows into the Gulf of Mexico. Mexico believed this was the border between Texas and Mexico.

Debates on slavery

Disputes over whether new territories acquired from the Mexican American War should allow slavery or be free states, intensifying sectional tensions in the U.S. in the mid-19th century.

Technology in Mexican American War

• Telegraph played crucial role in communication

• Railroads facilitated troop movement

• Steamships aided in transportation of soldiers and supplies

• Weapons like rifles and cannons advanced military tactics