I recently had a student email me who is interested in mapping land cover in the southeastern US for the last 30-or-so years.  He was looking for existing data for GA, AL, SC, and FL that he could use.  Locating such data for each state is a tall order, but here are some sources that may be of assistance.

GIS DATA

• 1992 NLCD
• 2001 NLCD
• 1992/2001 NLCD Retrofit
• GAP (FTP download)
• USGS Land Cover Institute

TABULAR SUMMARIES

• USDA Forest Service FIA Summaries (search for 'florida forest statistics' or 'georgia forest statistics' or 'forest statistics' for any of the other states you are interested in)
• NRCS Land Cover / Land Use Statistics
• NRCS Geospatial Data Gateway (access to current and some historical aerial photos)

GEORGIA DATA

• CSAT (look at the 'landuse / landcover' section)
• Georgia GIS Data Clearinghouse (search for  'land cover' or 'landuse')