deLesseps Story Morrison, Sr., known as Chep Morrison, was an American attorney and politician, who was the 54th mayor of New Orleans, Louisiana from 1946 to 1961. He then 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 1950. Morrison ran three primary campaigns for the Louisiana Democratic gubernatorial nomination, but was unsuccessful. Louisiana's African Americans had been effectively disfranchised by the turn of the 20th century; their initial preference for the Republican "Party of Lincoln", coupled with white voters' overwhelming support in the South for the Democratic Party, meant that the Democratic primary was the only competitive election in the state.