The Territory of Alabama was established March 3, 1817. Admitted as the 22nd state, Alabama achieved statehood December 14, 1819. (ALE; Wiki)
The graph displays the other subjects mentioned on the same pages as the subject "Alabama". If the same subject occurs on a page with "Alabama" more than once, it appears closer to "Alabama" on the graph, and is colored in a darker shade. The closer a subject is to the center, the more "related" the subjects are.