State, southern U.S. Area: 47,716 sq mi (123,584 sq km). Pop. (2009 est.): 4,492,076. Capital: Baton Rouge. Louisiana lies on the Gulf of Mexico and is bordered by Arkansas, Mississippi, and Texas. It can be divided physically into the Mississippi River flood plain and delta and the low hills of the Gulf of Mexico coastal plain. It is the only U.S. state to be governed under the Napoleonic Code. Indian occupancy in the area probably spanned 16,000 years; at the time of European settlement the region was inhabited by the Caddo and Choctaw. French explorer La Salle descended the Mississippi River in 1682 and claimed the entire river basin for France. The city of New Orleans was founded in 1718, and Louisiana became a French crown colony in 1731. Colonization increased in the 1760s with the arrival of French-speaking Acadians (Cajuns) from Nova Scotia. Spain controlled the territory from 1762 to 1800; then it passed back to the French. The lands that constitute modern Louisiana were acquired by the U.S. as part of the Louisiana Purchase in 1803 and became the Territory of Orleans in 1804. Louisiana became the 18th U.S. state in 1812. It seceded from the Union in 1861 at the start of the American Civil War and was readmitted in 1868. The plantation economy continued with the farmer class denied land ownership, which contributed to the rise of the populist Huey Long in the 1920s. After World War II Louisiana experienced more rapid development with the rise of offshore oil and gas drilling. Soybeans are a major agricultural crop; tree farming and shrimp fishing are also important. Petroleum and natural gas are the chief mineral resources. In 2005 hurricanes devastated New Orleans and surrounding communities.