Montgomery graduated from West Point in 1903 and was commissioned in the 7th Cavalry Regiment. In 1907, he married Virginia Lee, daughter of Major General Fitzhugh Lee.[3] They had two sons and two daughters.[4]
During World War I, Montgomery served with the American Expeditionary Forces in France, receiving a temporary promotion to colonel and the Distinguished Service Medal. From July 2, 1924, to March 13, 1927, he was commanding officer of the 1st Squadron, 10th Cavalry at Fort Huachuca. In 1927, Montgomery retired from military service as a lieutenant colonel. In 1929, he joined First Boston Corp, retiring in 1946 as a vice president. In 1930, Montgomery was advanced to colonel on the Army retired list.[5][6][7]
^Official Army Register. Washington, D.C.: U.S. Government Printing Office. 1 January 1940. p. 1092. Retrieved 22 September 2022.
^"Class of 1903—Register of Graduates". Official Register of the Officers and Cadets. United States Military Academy. 1971. p. 311. Retrieved 22 September 2022.