The Chiricahua Apaches, including leaders such as Cochise and Geronimo, resisted growing threats to their land and way of life as explorers, prospectors, settlers, and merchants moved westward through Apache Pass. The Butterfield Overland Trail, built in 1858 through the heart of the pass to link the East and California, intensified conflict, and Apache attacks on traveling parties and raids on settlements followed. The Bascom Affair in early 1861 further escalated hostilities. In 1862, a Union Army regiment from California marched through Apache Pass to oppose the Confederate invasions of New Mexico, and after an ambush near Apache Spring, established Fort Bowie to protect the water supply and the major southern transportation route. For the next 24 years, soldiers pursued the Apache, while broken government promises, rising discontent, and harsh reservation conditions led to violent uprisings and escapes. After Cochise died of natural causes in 1874, any hope of peace was lost, and it ultimately took General George Crook, Nelson Miles, and several thousand troops to secure the final Chiricahuas Apache surrender in 1886. Geronimo and his diminishing band then came to Fort Bowie in defeat on their way into permanent exile, ending the Apache Wars. Fort Bowie remained in use until 1894.