The last major Indian campaign took place in the Southwest. Kit Carson’s Civil War campaign had subdued the Navajo and the Mescalero Apaches, but the Chiricahua Apaches remained unbroken. Led by Chief Cochise, they terrorized parts of Arizona and New Mexico until the only white man Cochise trusted, Thomas Jeffords, persuaded him to make peace and accept a reservation on traditional Chiricahua land (1872), where Jeffords served as the Indian agent. But the forced transfer of the Chiricahua to the San Carlos reservation two years after Cochise’s death (1874), led to a renewal of raiding, this time under the principal leadership of warrior chief, Geronimo. for nearly a decade, Geronimo and his “renegade Apaches” kept U.S. and Mexican Army units busy, waging skillful guerrilla warfare characterized by rapid movement and carefully-laid ambushes. The number of his pursuers had grown to more than 5,000 before Geronimo finally surrendered his little band of less than 50 in September, 1886 to end the Apache wars. Geronimo and his “hostiles,” together with many “friendly” Chiricahuas, were imprisoned in Florida and then Alabama, before being moved in 1894 to Fort Still, Oklahoma, where Geronimo died in 1909. Despite his status as a “prisoner of war,” Geronimo became a popular figure, making appearances at the 1904 St. Louis World’s Fair and President Teddy Roosevelt’s 1905 Inaugural Parade.

The Mexican War of 1846-1848 broke out ostensibly over a dispute about the Texan boundary. But it really originated in the expansionist spirit of “manifest destiny,” of which President James K. Polk was a leading proponent. Polk came to office determined to acquire the Mexican provinces of California and New Mexico and when Mexico refused to sell them, used a border clash as a pretext for war. Although American opinion was deeply divided over the conflict, the war turned out to be a succession of triumphs for American arms. The two provinces Polk coveted were easily overrun: General Zachary Taylor overwhelmed a much larger Mexican army at Buena Vista (February 1847); and General Winfield Scott’s seaborne expedition to Vera Cruz fought its way into the heart of Mexico against superior forces and captured Mexico City (September 1847), forcing Mexico to make peace. By the Treaty of Guadalupe-Hidalgo (February 1848), Mexico ceded the territories of California and New Mexico and acknowledged the Rio Grande as the Texas boundary. While the war brought the U.S. vast territorial gains — extending America’s western boundary to the Pacific — it also revived the simmering conflict over slavery and its extension to new territories.

A unique breed of tough, self-reliant loners, the trappers and pioneers who called themselves “mountain men” became in the 1820s and 1830s the trail blazers of the Far West. Chafing at the restraints of settled society and attracted by the West’s profusion of wildlife, they went in search of beaver pelts and other furs, some as members of the fur companies but many independently. They learned Indian languages and customs, often married Indian women, and generally came to resemble Native Americans in dress, eating habits and fighting methods. Spending most of their time in the wild, mountain men gathered each summer at a prearranged spot for the annual rendezvous. There, joined by traders, fur company representatives, and Indians, they traded, drank, gambled and caroused in a raucous celebration.

Several mountain men won fame as explorers. Thus James Bridger (1804-1881) became the first white to visit the Great Salt Lake (1824); Jedediah S. Smith (1798-1831) rediscovered the South Pass (1823-1824), and later led a party through the Great Basin and Mojave Desert into California (1826); Kit Carson (1809-1868) blazed trails in the province of New Mexico (1826-1831); and Joseph Reddeford Walker journeyed from the Rockies to the Pacific, camping near Yosemite Valley in 1833.