Crawford served as a Second Lieutenant in the 10th Infantry on the United States frontier between 1889–1895, which included military police duty in Oklahoma City until 1890 and assisting the U.S. Commission in dealings with American Indian tribes; between 1891–1892 he organized an Apache Indian Company in the 10th Infantry. During the Spanish–American War he participated in the Battle of San Juan Hill (1898) and was later commended for his bravery. Between 1903–1907 he taught at Fort Leavenworth, Kansas in the Infantry and Cavalry School and the Army Staff College. Crawford also served in the Philippines a number of times, first during 1890–1902 and again between 1909–1911. From 1913–1916 Crawford served on the General Staff of the U.S. Army, after which he was in Panama Canal Zone until 1917. During World War I, Crawford served with the American Expeditionary Force as a Brigadier General of the National Army. There he commanded the 6th Infantry Brigade, 3rd Infantry Division during the Second Battle of the Marne. In 1919, Crawford retired due to disabilities.