How James K. Polk Led the US into War with Mexico

Polk's Path to the Mexican-American War

Manifest Destiny

Polk strongly believed the US was destined to expand across the continent, including Texas (annexed 1845).

Texas Annexation

Mexico viewed annexation as an act of war and severed diplomatic relations.

Border Dispute

Mexico claimed the Nueces River as the border; the US claimed the Rio Grande.

Provocation

In 1846, Polk ordered General Zachary Taylor to march to the Rio Grande—seen by Mexico as an invasion. Mexico declared war.

Outcome

Two-year war; US victory; gained California, Arizona, New Mexico, Utah, and more.