John Horton Slaughter, also known as Texas John Slaughter, was an American lawman, cowboy, poker player and rancher in the Southwestern United States during the late 19th and early 20th centuries. After serving in the Confederate States Army during the American Civil War, Slaughter earned a reputation fighting hostile Indians and Mexican and American outlaws in the Arizona and New Mexico territories. In the latter half of his life, he lived at the San Bernardino Ranch, which is today a well-preserved National Historic Landmark in Cochise County in far southeastern Arizona. In 1964, he was inducted into the Hall of Great Westerners of the National Cowboy & Western Heritage Museum.

San Bernardino Ranch is a historic ranch house in the southern San Bernardino Valley near the San Bernardino National Wildlife Refuge in extreme southeast Cochise County, Arizona, United States. It is significant for its association with the beginning of cattle ranching in southern Arizona and northern Mexico. The ranchland and valley are part of the headwaters region of the Yaqui River.