John M. Clark was born on Nov. 1, 1893, in Lockhart, Texas. He enlisted as a flying cadet on Sept. 22, 1917, and was commissioned a first lieutenant in the Aviation Section, Signal Reserve, on Nov. 13, 1917.
He received his ground school training at Kelly Field, Texas, and upon completing the flying course there he was assigned to at Kelly Field. He transferred to Brooks Field, Texas, in January 1919, returning to Kelly Field in March 1919. In July 1919 he was assigned to the El Paso, Texas, Airdrome. From January 1920 to October 1920 he served with the 1st Surveillance Group at Fort Bliss, Texas. He then was assigned to the Aviation General Supply Depot at San Antonio, Texas.
In May 1921 he went to France Field, Panama Canal Zone, for duty with the 6th Observation Group. Returning to the United States in May 1924, he was assigned to the San Antonio, Texas, Air Intermediate Depot, and in August 1926, he became Assistant Supply Officer of Kelly Field, Texas. He was named Supply Officer there in July 1927.
In November 1929 he became Supply Officer of the Fairfield Air Depot in Ohio, and in November 1930 was sent to Mather Field, Calif., to command the 80th Service Squadron. In November 1932 he was sent to Barksdale Field, La., to command the 77th Pursuit Squadron.
From August 1935 to June 1936 he attended the Air Corps Tactical School at Maxwell Field, Ala. Upon graduation there he returned to San Antonio, Texas, for duty at the Air Depot there as Supply Officer. In May 1940 he assumed command of Middletown Air Depot in Pennsylvania. In December 1941 he was assigned as Commanding Officer of the Sacramento Air Depot, Calif. He became Commanding Officer of the IV Air Service Area Command in May 1942, and was later given an unannounced overseas assignment.
He is rated a command pilot and combat observer.
On April 25, 1944, General Clark was awarded the Legion of Merit, "For exceptionally meritorious and distinguished service from December 1942 to June 1943, as Chief of Maintenance Repair Division, Headquarters Eighth Air Force Service Command. General Clark conceived, planned and developed mobile repair units designed to bring repair facilities to crash landed aircraft, thereby effecting a saving of two-thirds non-operational time. His conception, energetic organization and capable direction of this plan resulted in the return to operations of 83 four-engine bombers not otherwise repairable and reflect great credit on the armed forces of the United States and himself.
He was promoted to captain on Oct. 11, 1918, and was commissioned a first lieutenant in the Air Service of the Regular Army on July 1, 1920; captain, May 25, 1930; major (temporary) from April 20, 1935, to Aug. 28, 1935, and then reverted back to his permanent captaincy; major (temporary), June 16, 1936; major (permanent), April 1, 1939; lieutenant colonel (temporary), March 11, 1940; lieutenant colonel (permanent), Aug. 4, 1941; colonel (temporary), Nov. 15, 1941; brigadier general (temporary), Oct. 31, 1942.