The following are known battles of the Mexican–American War. This list includes all major engagements and most reported skirmishes. Included also are two major engagements, the Battle of Palo Alto, and the Battle of Resaca de la Palma, which took place prior to the official start of hostilities between the two countries.
The Mexican–American War lasted from 1846 until 1848. It grew out of unresolved border disputes between the Republic of Texas and Mexico after the annexation of the former by the United States during the Texas Revolution of 1836. Before 1836, Anglo settlers in Texas (which was then a part of Mexico) had increasingly desired to align with the United States and its ongoing westward expansion. Texas was admitted into the United States in 1845 and as a consequence, tension with Mexico increased over the disputed border.
The U.S. government claimed that the southern border of Texas was the Rio Grande; Mexico maintained it to be the Nueces River. The U.S. Congress declared war on May 13, 1846, while Mexico did so on May 23. Most of the formal fighting effectively ended in October 1847, soon after General Winfield Scott and his forces had stormed Mexico City. The Treaty of Guadalupe Hidalgo was signed on February 2, 1848 in which Mexico, under pressure, surrendered a vast tract of land to the United States for the sum of USD $15 million.