Clayton Campbell was born on March 14, 1917, in St. Maries, Idaho. After completing his bachelor's degree at the University of Idaho, he enlisted in the Aviation Cadet Program of the U.S. Army Air Corps on June 22, 1940. He was commissioned a 2d Lt and awarded his navigator wings on June 24, 1941, and then served as a B-25 Mitchell navigator with the 37th Bomb Squadron at Pendleton Field, Oregon, from June 1941 until he was selected for the Doolittle Mission in February 1942. Lt Campbell was the navigator on the 13th B-25 to take off from the aircraft carrier USS Hornet (CV-8) on April 18, 1942, and after bombing enemy shipping and supplies at the Yokosuka Naval Base in Japan, the crew flew to China and bailed out when their aircraft ran out of fuel. He remained in the China-Burma-India Theater flying combat missions until he returned to the United States in June 1943, and he left active duty and joined the Air Force Reserve on December 28, 1945, retiring from the reserves in 1963. Clayton Campbell died on November 17, 2002, and was buried at the Dry Creek Cemetery in Boise, Idaho.

His Silver Star Citation reads:

On July 16, 1942, this crew participated in a raid against the Japanese Concession in Hankow, China. The actual bombing of Hankow was performed in the face of heavy anti-aircraft fire, but so precisely did every member of this crew perform his assigned duties, that every bomb dropped was seen to land directly in the target area. This one mission was responsible for the destruction of large quantities of gasoline and other war supplies, in addition to several hundred enemy casualties, and further resulted in shattering the enemy's confidence in their protection against air raids, as evidence by Chinese Intelligence reports confirming the results of this raid. Such gallantry in action in the face of heavy anti-aircraft fire while carrying out a successful attack in an area known to be defended by superior numbers of enemy fighters is characteristic of the finest traditions of the Army Air Forces.