Kimble graduated from the United States Military Academy at West Point, New York, in June 1918 with the lowest grades in his class.

During World War II, he commanded the Air Corps Advanced Flying School where the Tuskegee Airmen were trained, and the island of Tinian, from which the atomic bombings of Hiroshima and Nagasaki were launched.

[2] His father died in 1901 and the family moved to Galveston, Texas, where Elvira's sister, Agnes von Harten, lived.

[3] Kimble entered the United States Military Academy at West Point, New York, on 15 June 1915, just three days after his older brother Edwin had graduated second in the class of 1915.

[4] During World War I, Edwin was attached to the British V Corps on the Western Front, and he died of sepsis after a surgical operation on 9 April 1918.

After graduation, he became an infantry instructor in trench mortars, one-pounders, hand grenades, bayonets, field fortifications and physical training, first at Fort Sill, and then at Camp Benning, Georgia.

[6][5] After the war ended, Kimble applied for a four-year secondment to the United States Army Air Corps, but his request was denied.

[4] In October 1922, Kimble entered the United States Army Air Service Primary Flying School at Brooks Field, Texas.

He was a student at the Air Corps Tactical School at Maxwell Field, Alabama, until 15 September 1934, and then a student at United States Army Command and General Staff College at Fort Leavenworth, Kansas, until 1 July 1936, after which he returned to the Air Corps Tactical School as an instructor in combat orders and naval operations.

While black personnel regarded his tenure negatively,[9] Kimble saw it in a positive light, later recalling: My work at the Tuskegee Flying School has been one of the most interesting experiences of my entire career.

I have enjoyed the work thoroughly and feel that I possibly have helped to some small degree advancement of the program at this station which is to train colored Americans to fly our fastest pursuit ships.

Kimble was promoted to brigadier general on 27 April 1943 and was awarded the Legion of Merit for commanding the Southwest Air Corps Training Center.