Apache Indians
National Archives and Research Administration

However, the addition of the Southwest to the United States also included tribes of Native Americans who had no hand in either the war or the Treaty. One provision obligated the U.S. to keep Apache Indians from raiding in Mexico, but the Apache economy was heavily dependent upon such raids. As American troops attempted to enforce their treaty obligation, a series of horrible wars erupted with the Apaches. By the time peace finally came in 1886, General William Tecumseh Sherman had declared that, having had one war with Mexico to win the territory, we ought to have another to make her take it back.

Oddly, the one region where federal Indian policy mattered little was Texas. Texas entered the United States retaining title to her public domain, the only state ever accorded this privilege. And when state authorities determined to exterminate or expel the native inhabitants, there was little the government in Washington could do. When Indian hater John Robert Baylor led an attack against a reservation of peaceable Brazos Valley Indians near Palo Pinto, federal troops stood by powerless. The state's Indian Agent, Robert Simpson Neighbors, helped his tribes escape to Indian Territory but was murdered on his return.