Actually, the biggest song about New Orleans is Johnny Horton's The Battle Of New Orleans, which spent six weeks at number one in June-July 1959. The Animals' song was number one for three weeks in September 1964. Third on the list would be Patti LaBelle's Lady Marmalade, which was number one for one week in March 1975. Next would be the Freddy Cannon song, which reached #3 in January 1960, and the Gary US Bonds song, which reached #6 in December 1960.
There are more than two hundred other songs about New Orleans, including Mardi Gras by Doug Kershaw, Ain't No City Like New Orleans by Earl King, Going Back To New Orleans by Leon Haywood, Midnight In New Orleans by Earl Hines, King Of New Orleans by Better Than Ezra, New Orleans Stomp by Louis Armstrong, New Orleans Low Down by Duke Ellington, New Orleans Ain't The Same by Fats Domino, Sweet Home New Orleans by Dr. John and Oh My NOLA by Harry Connick Jr.