In 1951, Hickey was officially assigned as chief of staff, receiving promotion to lieutenant general. He served under MacArthur's successors, Matthew Ridgway and Mark Clark, and played an important role in the planning and execution of operations during the Korean War. General Hickey's decorations included two awards of the Distinguished Service Medal, four of the Silver Star, the Legion of Merit and the Bronze Star. General Hickey retired from the military in 1953, and became an executive with the Continental Motors Corporation. In his later years, he resided in Pass Christian, Mississippi. Hickey died at Ochsner Foundation Hospital in Jefferson, Louisiana on October 20, 1961. He was buried at Live Oak Cemetery in Pass Christian. On April 30, 1917, Hickey married Sophronia Purdue Brown of Indianola, Mississippi. They had no children.