Mexican War, 1846-1848

War with Mexico broke out in 1846 after the United States formally annexed Texas.  Although historians consider the Mexican War (1846-1848) primarily as a pretext for American expansion, at the time many Americans patriotically supported the cause.  President James K. Polk immediately called upon state governors to provide 50,000 volunteers to aid the regular army, with New York State to provide seven regiments.  Eventually, New York State supplied two full volunteer regiments under colonels Jonathan Stevenson and Ward Burnett.  Stevenson’s regiment mostly served as an occupation force in Lower (Baja) California, while Burnett’s New Yorkers participated in some of the fiercest fighting of the war, earning praise for their courage and performance.       

The Mexican War lasted less than two years and tremendously increased the size of the United States by adding 1.2 million square miles of territory including the present-day states of California, Nevada, Utah and large parts of Colorado, Arizona and New Mexico.  In addition, the temporary deployment of state volunteers and their solid performance established a pattern for using state militia forces and volunteers that would continue with the Civil War and the Spanish-American War.