Al·a·bam·a: n. - A state of the southeast United States. It was admitted as the 22nd state in 1819. At one time a tribe of the Creek confederacy formerly inhabiting southern Alabama and now located in eastern Texas. Alabama was first explored by the Spanish, and the southern section was claimed by the United States as part of the Louisiana Purchase (1803). Montgomery is the capital and Birmingham the largest city. Population between 4-5 million.