Charles Edward Hart was born in Fort Washington, Maryland, the son of Dr. James William Hart and Grace Duncan Hart. Hart was a descendant of Private Joseph Hart, a member of the 4th Virginia Regiment during the Revolutionary War. By 1910 the family had moved to Washington, D.C. where Hart's father had a general practice and served on the staff of the Veteran's Hospital. Eventually residing in Fort Hunt, Virginia, Hart would attend military drills with his father. After graduating from Western High School in Washington, D.C., Hart began working at a bank while seeking an appointment as a cadet at United States Military Academy.
On January 31, 1941, Hart received a temporary promotion to the rank of Major. Later that year, while serving as an instructor in the Department of Gunnery at the United States Army Field Artillery School, Hart received a permanent promotion to Major on June 12, 1941. He was then sent to Fort Leavenworth, Kansas to attend the Command and General Staff School. Upon completing the course, he was again assigned to the Artillery School, this time as an instructor in the Department of Tactics. With America's entry into World War II in 1941, the military suffered from a lack of qualified officers to take command positions. It was under these circumstances in 1941 that Hart received a promotion to the temporary rank of Lieutenant Colonel on December 24, 1941. He would then be transferred to the II Corps during the planning for the invasion of North Africa where he would initially serve as the Assistant Commander of the II Corps Artillery. With the commencement of Operation Torch and the invasion of Algiers the II Corps under Major GeneralLloyd Fredendall would be designated the Central Task Force for the invasion. It was during the operations in North Africa that Hart was elevated to the position of commander of the II Corps Artillery. On January 12, 1943, Hart was given a temporary commission of Colonel and continued in command of the II Corps Artillery. As the II Corps’ Artillery Officer he was involved with the operations of the II Corps during the drive towards Tunis, including the U.S. defeats at the Battle of Sidi Bou Zid on February 14–17, 1943 and Kasserine Pass on February 19–22, 1943. Following the Allied defeats in February, Major General Lloyd Fredendall was transferred from command of the II Corps and replaced by Major General George S. Patton on March 6, 1943. With Patton in command, Hart moved to improve artillery operations. Concerned with his artillery air observation posts, he requested and received permission to add an air artillery officer to his staff. On March 8, 1943, Lieutenant Delbert L. Bristol was assigned on temporary duty. Under Hart's direction and with the blessing of Patton, Bristol developed the first Corps Air Artillery section in the entire U.S. Army.