The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state. Kentucky is one of four U.S. states constituted as a commonwealth (the others being Virginia, Pennsylvania, and Massachusetts). Originally a part of Virginia, in 1792 it became the 15th state to join the Union. Kentucky is the 37th largest state in terms of total area, the 36th largest in land area, and ranks 26th in population.