The American alligator (Alligator mississippiensis) suffered noticable population declines by the 1950s and 1960s due to habitat loss and unregulated or poorly regulated hunting . In 1967 it was listed as an endangered species throughout its range in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, and Texas. Populations began to rise and the species was delisted in three Louisiana parishes in 1975 , downlisted in Florida and certain coastal areas of South Carolina, Georgia, Louisiana, and Texas in 1977 , delisted in nine additional Louisiana parishes in 1979 , delisted in the 52 remaining Louisiana parishes in 1981 , delisted in Texas in 1983 , delisted in Florida in 1985 , and delisted in the remaining portion of its range (Alabama, Arkansas, Georgia, Mississippi, North Carolina, Oklahoma, and South Carolina) in 1987 . To protect it from accidentatl shooting, it remains protected under the Endangered Species Act due to its similarity of appearance to the endangered American crocodile .
Alligator surveys are generally not comparable due to differences in effort and methodology. Florida established a standardized monitoring program in 1974 . It documents a steady increase in density of wild alligators over one foot in length per linear kilometer of shoreline between 1974 and 1992, though the density declined somewhat from the 1987 peak of nine to seven in 1992.
 U.S. Fish and Wildlife Service. 1987. Reclassification of the American alligator to threatened due to similarity of appearance throughout the remainder of its range. June 4, 1987 (52 FR 21059)
 U.S. Fish and Wildlife Service. 1975. Reclassification of the American alligator in Louisiana, and proposed changes to special rules concerning the alligator. September 26, 1975 (40 FR 44412)
 U.S. Fish and Wildlife Service. 1977. January 10, 1977 (42 FR 2071)
 U.S. Fish and Wildlife Service. 1979. June 25, 1979 (44 FR 37130)
 U.S. Fish and Wildlife Service. 1981. Reclassification of American alligator in Louisiana. August 10, 1981 (46 FR 40664)
 U.S. Fish and Wildlife Service. 1983. October 12, 1983 (48 FR 46332)
 U.S. Fish and Wildlife Service. 1985. Reclassification of American alligator in Florida to threatened due to similarity of appearance. June 20, 1985 (50 FR 25672).
 Woodward, A.R. and C.T. Moore. 1995. American Alligators in Florida; in LaRoe, E.T., G.S. Farris, C.E. Puckett, P.D. Doran, and M.J. Mac, eds. 1995. Our living resources: a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems. U.S. Department of the Interior, National Biological Service, Washington, DC. 530 pp. http://biology.usgs.gov/s+t/noframe/d052.htm