Morgan next held various staff positions, including that of assistant to U.S. Army Lieutenant General Dwight D. Eisenhower in planning the invasion of North Africa (Operation torch). Promoted to temporary lieutenant general in 1942, Morgan was named chief of staff to the supreme Allied commander (COSSAC) in March 1943 and charged with developing the plans for the cross-Channel invasion of France (Operation overlord). Morgan and his planners eventually selected Normandy as the site for the invasion and planned a three-division initial landing and the use of artificial harbors (Mulberries). Later, British General Bernard Montgomery criticized Morgan for having come under Supreme Commander General Dwight D. Eisenhower's "spell" and insisted that the invasion front be expanded and the force increased to five divisions.
In January 1944, Morgan was "promoted" to deputy chief of staff to Eisenhower, a post he filled until the end of the war. He retired in 1946 and served briefly as head of the UN Relief and Recovery Administration in Germany. Between 1951 and 1956, he played an important role in the development of British atomic energy. He died in Northwood, Middlesex, England, on 19 March 1967.
John F. Votaw
Harrison, Gordon A. Cross-Channel Attack: The European Theater of Operations, United States Army in World War II. Washington, DC: Center of Military History, U.S. Army, 1989.; Morgan, Sir Frederick. Overture to Overlord. Garden City, NY: Doubleday, 1950.; Pogue, Forrest C. United States Army in World War II: The European Theater of Operations—The Supreme Command. Washington, DC: Office of the Chief of Military History, Department of the Army, 1954.