 Following his Navy retirement, Cooke headed the Department's Office of Organizational and Management Planning, a job that evolved into his final post.In this position, Cooke was responsible for the physical plant and personnel administration of the Pentagon.His responsibilities for security, maintenance, and operations in the building earned him the title "Mayor" - the phrase "Mayor of the Pentagon" had often been used to refer to him during his tenure, a nickname that continued to be used for those who held the position after him, including Raymond F. DuBois.