Stoneman mustered out of volunteer service on September 1, 1866 and reverted to the regular army rank of colonel. In 1869, the Army transferred him out west to command the District of Arizona (1869-1870) and subsequently the Department of Arizona (1870-71). Stoneman was relieved of his command due to controversies surrounding his handling of the region's Indians, including the Camp Grant massacre. On August 16, 1871, Stoneman was granted a disability retirement at his brevetted rank of Major General. Three days later, however, President Ulysses S. Grant revoked his disability licence, forcing him to retire at the rank of colonel.