Fort Grant, located in the U.S. state of Arizona, is a state prison and a former United States Army fortification. Fort Grant began its life as an Old West outpost in Arizona Territory, built in 1860 at Aravaipa Canyon originally as Camp Grant.

In 1872 after the Camp Grant Massacre and prior to the closure of old Fort Grant (Fort Breckinridge), a site was chosen for the new fort by General George Crook. The "new" site was at a higher elevation and was a more strategic location, situated at the foot of the southwestern slope of Mount Graham in what is now Graham County in southeast Arizona. Founded along a route that was often used by Apaches fleeing to Mexico from the San Carlos Reservation, the fort’s purpose was stop the marauding bands of Apache Indians in western New Mexico and southeast Arizona.  The fort was strategically placed so as to protect settlers who were constantly harassed by these Apache warriors. It played a prominent role in the Apache Wars of the 1880s. 

Troops patrolled Southeast Arizona and Western New Mexico, chasing small marauding bands of Apache Indians and keeping the peace. Fort Grant was a hub of activity during the Apache Campaigns. It boasted a quartermaster store second to none. The building later called Brown's Folly was over 200 feet long and 40 feet wide. It was constructed of solid stone and is still in use. Troops from Fort Grant participated in the military campaign against Geronimo which ended with Geronimo's surrender in August of 1886. In 1888, the Buffalo Soldiers of the 10th Cavalry were used in civil duties and for chasing train robbers. On May 11, 1889, Paymaster Major Wham was robbed of $29,000 in gold and silver coins while en route to pay the soldiers at Fort Thomas and Fort Apache.

Edgar Rice Burroughs was stationed at Fort Grant in 1896 as an enlisted man after failing the exam for entrance to West Point. He was discharged in 1897 after being diagnosed with a heart condition that made him ineligible for a commission.

The Fort was reproposed in 1900 as a staging point for soldiers going to the Philippines to fight in the Philippine–American War.

Fort Grant was abandoned by the Army in 1905. In 1912, Arizona gained statehood, and the fort was occupied by the Fort Grant State Industrial School, which modernized most of the buildings. In 1968, the state of Arizona officially assigned the site to the Department of Corrections, and in 1973 Fort Grant became a state prison for male convicts.

 In 1876, the notorious Billy the Kid (also known as Henry McCarty, Henry Antrim and William H. Bonney ) settled in the vicinity of Fort Grant Army Post, where he worked local ranches and tested his skills at local gaming houses. During this time, McCarty became acquainted with John R. Mackie, a Scottish-born ex-cavalry private with a criminal bent. The two men supposedly became involved in the risky, but profitable, enterprise of horse thievery and targetting local soldiers.  McCarty was involved in an altercation with a bullying civilian blacksmith at Fort Grant, whom he shot in self-defense. The Kid then fled Arizona Territory and entered New Mexico Territory.

In January, 1873, eleven companies of cavalry and infantry were transferred to Fort Grant, under the command of Major Brown. The troops immediately began to establish additional buildings including officers’ quarters and a commissary building, as well as constructing a wagon road up the side of Mount Graham. From the beginning, the soldiers were tasked with intercepting the Indians escaping from the San Carlos Reservation and pursuing raiding parties along the international boundary. The troops played a prominent role in the Apache Wars of the 1880s.

Following the Battle of Cibecue on August 30, 1881, three White Mountain scouts by the names of Dead Shot, Dandy Jim and Skitashe, were court martialed for their part in the mutiny. The three scouts were hanged on a specially constructed gallows on the parade ground on March 3, 1882 as scores of civilians from the surrounding countryside looked on. The Cibecue affair touched off a general outbreak that saw Chiricahua and Warm Springs Apaches such as Naiche, Juh, and Geronimo bolt the reservation and plunge Arizona, New Mexico, and northern Mexico into years of turmoil. The campaign against the Apaches would continue until it finally ended with Geronimo's surrender in August of 1886.

U.S. garrison at Fort Grant during the Apache Wars, circa 1885.

In 1888, Buffalo Soldiers of the 10th Cavalry were stationed at Fort Grant who often participated in civil duties, such as chasing train robbers and other outlaws. One high profile case was the infamous Wham Paymaster Robbery which occurred on May 11, 1889. After US Army Paymaster Major Joseph W. Wham, had paid the salaries of the soldiers at Fort Grant, he along with an escort of eleven Buffalo Soldiers, were making their way to Fort Thomas, when they were ambushed 18 miles from their destination. The soldiers soon found themselves in a lengthy gun battle with the robbers, which resulted in eight of them being wounded. The bandits, in the meantime, made off with $28,000 in gold and silver coins.

 The troops were withdrawn from Fort Grant in 1898, and the site was empty, but for a caretaker by the name of Colonel William F. Stewart in the Artillery Corps. However, two years later, in 1900, the post became a staging point for numerous soldiers on their way to the Philippines to fight in the Spanish-American War. In October, 1905, Captain Jenkins marched Troop D across the parade grounds of Fort Grant for the last time. The soldiers were then transferred to Fort Huachuca and the post was once again abandoned except for a caretaker.

After Arizona became a state on February 14, 1912, the government turned over the site to the State of Arizona for use the Arizona State Industrial School for wayward boys and girls. The school quickly began to modernize the buildings for new purposes. In 1968, the school officially became part of the Arizona State Department of Corrections and in 1973, became an adult male prison. In 1997 the prison became a unit of an Arizona State Prison complex headquartered in Safford, Arizona. Over the years, extensive construction programs have destroyed many of the historic buildings, but several of the original adobe officers’ quarters are still utilized today. The prison is located on Arizona State Road 266 about 36 miles southwest of Safford, Arizona.