He is most noted as commanding general of the Field Artillery School at Fort Sill, Oklahoma, at the beginning of World War II.

He attended the University of Iowa and entered the United States Military Academy with the first contingent of senatorial appointments in 1900.

[4][1] The citation for his Army DSM reads: The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Army Distinguished Service Medal to Brigadier General George R. Allin, United States Army, for exceptionally meritorious and distinguished services to the Government of the United States, in a duty of great responsibility during World War I.

As Executive Officer and Director of Training in the Office of the Chief of Field Artillery from 21 March 1918 to 1 September 1918, by reason of his high professional attainments, ability, foresight, and judgment, General Allin rendered invaluable aid in solving the many complex problems confronting his arm of the service.

[1] Originally buried near his parents in Mason City, Iowa, his remains were reinterred at the West Point Cemetery on December 15, 1987[7] along with those of his wife Jessie Cooper (Pontius) Allin (1880–1963).