This paper will briefly examine the battles between the armies of Mexico and the United States during the war between Mexico and the United States in 1846 and 1847. The discussion will focus upon the campaigns in northern and central Mexico because the major battles took place during these campaigns. The rest of the southwest region saw only minor actions, particularly guerrilla raids; this area was ceded to the United States largely as a result of the U.S. victories to the east. The ports of California were occupied by the U.S. Navy shortly after the beginning of hostilities and only small ground forces were sent to the west coast by the U.S. government.
As tensions between the U.S. and Mexico increased during the Winter and Spring of 1846, the U.S. government began preparing for hostilities. In March of 1846, President James Polk ordered Major General Zachary Taylor into the Texas region as leverage for negotiations. Although specifically instructed to defend Texas against invasion, Taylor was implicitly instructed to invade Mexico if necessary. U.S. naval forces in the Pacific were ordered to seize the California ports should war break out. As events began pointing towards war, President Polk ordered the Navy to blockade the Mexican coastline and the Army to occupy the provinces of northern Mexico.
Immediately upon receipt of his orders, Taylor marched his army south from Corpus Christi and established a base camp at Fort Brown, opposite the Mexican forces at Matamoros. After failing to take this position in an attack, the Mexican forces under General Mariano Arista took up a position at Palo Alto, between Taylor and Fort Brown. On May 8 the two forces fought an inconclusive battle at Palo Alto; although the American army held the battlefield, they Mexican army remained intact at the end of the day. Arista withdrew his force behind Resaca de la Palma, a defensible ravine. The next day the American force attacked...