Bryan was with the portion of the Class of 1923 that graduated after accelerated course of studies in three years, receiving a commission as a second lieutenant of artillery.

After graduation from West Point, Bryan took artillery officer training at Fort Sill, Oklahoma.

[1] In 1940, Bryan was promoted to major and graduated from the United States Army War College.

In 1942 he was promoted to colonel and assigned as Chief of the Aliens Division for the Provost Marshal General's Office.

He then took on a leading role on the military armistice commission of the United Nations that concluded hostilities in Korea in 1953 and directed the repatriation of prisoners of war.