DeLesseps Story Morrison deLesseps Story "Chep" Morrison, Sr., (January 18, 1912 — May 22, 1964) was an attorney and politician, the mayor of New Orleans from 1946 to 1961. He also served as an appointee of U.S. President John F. Kennedy as the United States ambassador to the Organization of American States between 1961 and 1963.New Orleans' peak population was reached during Morrison's mayoralty, when the 1960 census recorded 627,525 inhabitants, a 10 percent increase from the 1950 figures.