The Cochise County Cowboys were a loosely associated group of outlaw cowboys in Pima and Cochise County, Arizona Territory in the late 19th century. The term cowboy had only begun to come into wider usage during the 1870s, and in the place and time, Cowboy was synonymous with rustler. Cattle thieves frequently rode across the international border into Mexico and stole cattle from Mexican ranches, which they drove back across the border and sold in the United States. Some modern writers consider them to be one of the first and earliest forms of organized crime syndicates in American history.
The Mexican government lowered tariffs and added forts along the border, and cross-border rustling and smuggling became less attractive. The Cowboys then began to steal cattle and horses from neighboring American ranches, reselling them to unscrupulous butchers. They held up stagecoaches, stole the strongboxes, and strong-arming passengers for their valuables. In some instances, they killed drivers and passengers.
Tombstone, Arizona, was one of the last frontier towns in the American Old West. Outlaws from all parts of the Western territories felt the pressures of encroaching civilization and the increased presence of lawmen and the courts, backed by growing populations of farmers and citizens desiring law and order. The town had boomed in less than 18 months from about 100 miners living in tents and shacks to more than 7,000 people by December 1, 1879, when Virgil, Wyatt, and Morgan Earp arrived in Tombstone.
Virgil Earp had been appointed Deputy U.S. Marshal for eastern Pima County in Prescott and directed to relocate to Tombstone to concentrate on suppressing the Cowboys' illegal activities. He arrived with his brothers Wyatt and Morgan. He appointed Morgan as an undersheriff, and Wyatt looked for business opportunities. When those didn't work out, Wyatt Earp started riding shotgun for Wells, Fargo & Co., guarding their silver bullion shipments. He was appointed as an assistant Pima County sheriff for a period, and Virgil Earp was hired as Tombstone's city marshal in the middle of 1881.