Statewide, regional, and county histories often have biographical sections that can be very helpful. A representative biographical encyclopedia for Florida is Harry Gardner Cutler, History of Florida, Past and Present . . . , Three Volumes (Chicago, Illinois and New York, NY: Lewis Publishing Company, 1923; FHL book 975.9 H2c; Volume 1 on film 1321188, Volume 3 on film 1697443 item 10). Volumes 2 and 3 have biographical information.
Helpful indexes available at the Family History Library and the St. Augustine Historical Society are the Biographical Card Index (on 18 FHL films beginning with 967146) and the alphabetical Biographical and Genealogical File (on 9 FHL films beginning with 967703).