Alabama is the thirtieth largest state in the United States with 52,423 square miles ( 135,775 kmÂ ) of total area . 3.19 % of the area is water , making Alabama twenty-third in the amount of surface water , also giving it the second largest inland waterway system in the United States . Alabama is the thirtieth largest state in the United States with 52,423 square miles ( 135,775 km2 ) of total area : 3.19 % of the area is water , making Alabama twenty-third in the amount of surface water , also giving it the second largest inland waterway system in the United States .