He attended the United States Naval Academy at Annapolis, Maryland, and graduated in June 1922 with the rank of second lieutenant in the Marine Corps.

Many of his classmates became general officers later: Hyman G. Rickover, Robert E. Blick Jr., Herbert S. Duckworth, Clayton C. Jerome, James P. Riseley, James A. Stuart, Frank Peak Akers, Sherman Clark, Ralph B. DeWitt, Delbert S. Cornwell, Frederick J. Eckhoff, Hugh H. Goodwin, John Higgins, Vernon Huber, Michael J. Malanaphy, William S. Parsons, Albert K. Morehouse, Harold F. Pullen, Harold R. Stevens, John P. Whitney, Lyman G. Miller and George J.

He returned to the United States in May 1926 and was assigned for mail guard duty at Brooklyn Navy Yard during a wave of armed robberies.

While aboard that ship, he participated in the patrol sea duty in the Pacific Ocean until July 1932, when he was appointed supply officer on the staff of 2nd Marine Brigade under Colonel Emile P. Moses.

In July 1937, Coffman was transferred to the Marine Barracks at Cavite, Philippine Islands, where he was appointed executive officer of the Naval prison.

At the outbreak of the World War II in September 1939, Coffman was appointed quartermaster of the Depot of Supplies at Naval Station Norfolk.

[5] Colonel Coffman stayed in San Francisco until June 1949, when he has been transferred to Washington, D.C., and assigned to the Headquarters Marine Corps for a brief period.

Last assignment of his career came in January 1952, when he was appointed commanding general of the newly commissioned Marine Corps Depot of Supplies Albany, Georgia.