Barry County, MO 

History books report that the Mexican War, a war between the United States and Mexico, began with a Mexican attack on American troops along the southern border of Texas on Apr. 25, 1846. And that fighting ended when U.S. Gen. Winfield Scott occupied Mexico City on Sept. 14, 1847; a few months later a peace treaty was signed on Feb. 2, 1848 at Guadalupe Hidalgo. In addition to recognizing the U.S. annexation of Texas, the defeated Mexico ceded California and New Mexico, which included all the present-day states of the Southwest, to the United States.