George Campbell enlisted in the 12th U.S. Infantry in 1889 to fight in the Sioux Indian Campaign. He served for twenty-two years and in six wars: the Indian Campaigns, the Philippines, and Cuba, and then China during the Boxer Rebellion. He then went to the Mexican Border fighting the armies of Pancho Villa and was instrumental in capturing the notorious Moro leader Faustino Alban. He then went back to the Philippines until he retired in 1908. In 1917 at the age of 48 he returned to military service with a commission, and was Killed in Action during World War I.