Introduction

In 1836, Americans living in the Mexican state of Texas had rebelled against the central government in Mexico City and established the so-called Lone Star Republic. When the United States annexed Texas in 1845 and made it a new American state, the United States also inherited a long-smoldering border dispute between the breakaway Texans and the government of Mexico. President James K. Polk, who had campaigned on a program of western expansion and believed that control over North America was the nation's " Manifest Destiny ," escalated the border dispute into a formal war in 1846. This module allows you to watch the three principal campaigns of that war unfold.