Lithograph entitled: "Storming of the Heights at Monterrey, September 21, 1846." In the Battle of Monterrey (September 21-24, 1846) General Pedro de Ampudia and the Mexican Army of the North was defeated by US forces under the command of Zachary Taylor and William J. Worth. General William Jenkins Worth overran Federation Hill in western Monterrey, while Taylor launched a diversion against eastern Monterrey. The Mexican-American War was an armed conflict between the United States of America and Mexico from 1846 to 1848 in the wake of the 1845 US annexation of Texas. Combat operations lasted from spring 1846 to fall 1847. American forces quickly occupied New Mexico and California and then invaded parts of Northeastern Mexico and Northwest Mexico. The Pacific Squadron conducted a blockade, and took control of several garrisons on the Pacific coast in Baja California. After Mexico would still not agree to the cession of its northern territories, another American army captured Mexico City, and the war ended in victory of the US. The Treaty of Guadalupe Hidalgo forced Mexican Cession of the territories of Alta California and New Mexico to the US in exchange for $18 million. In addition, the United States forgave debt owed by the Mexican government to US citizens. Mexico accepted the Rio Grande as its national border, and the loss of Texas.