The United States’ war with Mexico (1846–48) was highly controversial. Like the War of 1812 before it, the declaration of war was opposed by many congressmen, and it excited numerous protests. The Polk administration asserted that the Mexican government of General Antonio Lopez de Santa Anna (the same dictator who had lost Texas) had started the war, by severing relations with the United States and raising an army to march to the border. Yet in the previous months, Polk had ordered General Zachary Taylor to march into territory along the Rio Grande River disputed by Mexico and the United States, seemingly in deliberate provocation of a war. Polk was a slaveholder, and though no record exists declaring his intentions, many southerners coveted additional slaveholding territory to be added to the United States in an effort to protect slavery from being legislated out of being.