A fighter pilot during his early years in the then-Army Air Corps, later Army Air Forces, McConnell gained broad experience through a variety of operational and administrative assignments, including duty as assistant executive in the Office of the Chief of Air Forces in Washington. Subsequently, he served in key Air Force positions in both Asia and Europe.[1]
In 1943 McConnell became chief of staff of the China-Burma-India Air Force Training Command at Karachi, India (later part of Pakistan), and remained in Asia for the rest of World War II. While senior air staff officer, Air Command Southeast Asia, and deputy commander of the Third Tactical Air Force in 1944, he participated in combat operations against the Japanese in Burma. In 1946 he was named senior air adviser to the Chinese government and, at the same time, commanded the Air Division, Nanking Headquarters Command.[1]
McConnell returned to Air Force Headquarters in Washington, D.C., in 1947 to become chief of the Reserve and National Guard Division and, the next year, was appointed chief of the Air Force's Civilian Components Group. Assigned to England in 1950, he served as deputy commander and later, commander of the Third Air Force. He then took command of the 7th Air Division of the Strategic Air Command, commanding the Third Air Force at the same time.[1]
The public library in his hometown of Booneville, Arkansas is named in his honor and contains many items of memorabilia from his years of service to the US Air Force, including service medals, decorations and commendations as of 2016.[9]
McConnell's role as Chief of Staff of the Air Force, as well as that of the other members of the Joint Chiefs of Staff during the Vietnam War, specifically under the administration of President Lyndon B. Johnson and Secretary of Defense Robert McNamara, has recently been the subject of significant historical research in the area of the relationships between senior military leaders (e.g., the JCS) and the civilian political leadership (e.g., the National Command Authority)[10] and has increasingly become a topical discussion issue and object lesson for officers attending the nation's senior service colleges (i.e., Air War College, Army War College, Naval War College and National War College).