The state lines of Louisiana were established when the state was admitted to the union on April 30, 1812, as the 18th state. It was previously part of a larger area known as the Louisiana Purchase.
Louisiana borders Texas to the west, Arkansas to the north, Mississippi to the east and the Gulf of Mexico to the south. The state covers 51,843 square miles, of which 43,566 are land and 8,277 are water, and it contains 64 counties. Major geographic features in Louisiana include Lake Pontchartrain, the Mississippi River and the Sabine River, which forms part of the state's border with Texas.