|Louisiana joined the Union in 1812 to become the 18th state of the United States of America. It is situated in the southern region of the country with a total area of 51,885 square miles. In terms of area, it is the 31st largest state of the nation while it ranks 25th in population with more than four million residents living across the state. Louisiana has Texas to its west, Arkansas to the north and Mississippi to the east. Its southern border opens to the Gulf of Mexico. The surface consists of the alluvial and the uplands. The alluvial region is comprised mainly of coastal marshlands, low swamp lands and beaches. Apart from this, the state also consists of barrier islands, which cover an area of about 20,000 square miles. Louisiana is the only state in the US that is divided into parishes, unlike others, which have counties as local forms of governance. Jefferson Parish is the largest parish by population whereas Cameron Parish is the largest in land area. The state presents an admixture of eighteenth century French, African and Spanish cultures. Among the cities in Louisiana, New Orleans is the largest in land area. The capital is Baton Rouge.