Louisiana, flag ofconstituent state of the United States of America (United States). It is delineated from its neighbours— Arkansas to the north, Mississippi to the east, and Texas to the west—by both natural and man-made boundaries. The Gulf of Mexico (Mexico, Gulf of) lies to the south. The area of Louisiana includes more than 3,000 square miles (7,770 square km) of inland waters. The capital is Baton Rouge.

With parts of its land lying farther south than any portion of the continental United States except southern Texas and the Florida peninsula, and with New Orleans, its largest city, lying on roughly the same parallel as Cairo, New Delhi, and Shanghai, Louisiana owes much of its complex personality to its geographic position. The subtropical climate of the state has provided the magnificent brooding scenery of the coastal bayous, and the lush, dank vegetation of its shores conceals a wealth of petroleum and natural gas. The fertile soil covering much of the terrain made Louisiana a rich agricultural area by 1860, with flourishing sugarcane and cotton plantations. A lumber boom occurred at the turn of the 20th century, and Louisiana underwent rapid industrialization after World War II. Mineral output is great, and the state ranks among the country's leaders in oil and gas production.

Three types of regions are found in Louisiana: lowlands, terraces, and hills. The lowlands consist of the coastal marshes and the Mississippi floodplain, with its natural levees and moderate relief. The Red River valley has a low-elevation relief, with red soils in its alluvial plain and many raft lakes built by impounding water from logjams. The terraces include much of the so-called Florida Parishes to the north and northeast of the Mississippi delta, as well as the prairies of southwestern Louisiana. Hills flank the Red River valley and lend contour to the northern portion of the Florida Parishes; the state's highest point is Driskill Mountain (535 feet 【163 metres】), in northwestern Louisiana.

Louisiana shares the general physiographic characteristics common to the Gulf Coast states of the southern United States, with the vital exception of the Mississippi River, which borders and then flows through the state and extends its delta far into the Gulf of Mexico. The changing course of this great North American river has created the huge Atchafalaya River basin and has dumped tons of sediment along the coast. Despite this, the beachless coast of Louisiana is eroding; at the end of the 20th century, land was vanishing at a rate of about 24 square miles (62 square km) per year. This loss has been caused in part by the system of levees (or embankments) constructed by the federal government to keep the Mississippi in a central channel, which left side channels open to erosion. In 2005 Hurricane Katrina (Katrina, Hurricane) eroded an additional 73 square miles (189 square km) of the Louisiana coastland.

Louisiana's climate is subtropical, a natural result of its location on the Gulf of Mexico. As it also lies at the mouth of the vast Mississippi-Missouri river valley, roughly halfway between the Atlantic and the Pacific oceans, the state is also affected by continental weather patterns. Hot, humid summers, tempered by frequent afternoon thunder showers, alternate with mild winters. Louisiana is subject to tropical storms, and the hurricane season extends for six months, from June through November. Average annual temperatures range from 64 °F (18 °C) in the extreme north of the state to 71 °F (21 °C) at the mouth of the Mississippi River. The highest monthly average is 82 °F (28 °C) in July, and the lowest is 50 °F (10 °C) in January. In summer it is the humidity, rather than the heat, that is one of the more marked characteristics of the state's subtropical climate. The frost season falls roughly between November 1 in northern Louisiana and December 14 in the extreme southeast. The average growing season ranges from 220 to 320 days and the average precipitation ranges from almost 45 inches (1,140 mm) at Shreveport to more than 56 inches (1,420 mm) at New Orleans.

Natural vegetation in Louisiana is found in three major divisions: the first consists of forest, upland pines and hardwoods, bottomland hardwoods, and bald cypress; the second consists of prairie, or dry grassland; and the third consists of marshland, or wet grassland. In the southern half of the state, along a zone running westward from Baton Rouge, live oaks with their characteristic drapings of Spanish moss predominate. The magnolia, whose blossom is the state flower, grows throughout the state.

Northern Louisiana forms a natural region including the northeastern Louisiana delta, the Red River valley, and the northern Louisiana hills. Southern Louisiana, composed of the parish of Avoyelles and all the parishes that lie south of latitude 31° N, has three major subregions: (1) the Florida Parishes in the east, (2) southwestern Louisiana, which contains many Anglo-Saxon Protestants but also has an important French minority, and (3) a region in between, variously known as Cajun country, the river and bayou country, or the sugar bowl.

The earliest settlements in the river and bayou parishes were “line” villages, where farmsteads were each built at the riverfront of a long and narrow lot, with the stream serving as a highway. The line village pattern contrasted with the irregular pattern stemming from the ancient land-division system of metes and bounds used by the Anglo-Saxons of the Florida Parishes. Where the natural levee was wide enough, plantations were established. Before the Civil War, people came to the uplands of northern Louisiana from the eastern states and settled in isolated farmsteads among the pine woods. Southwestern Louisiana was developed after 1880, and its prairies were converted into rice fields. Settlement there resembled a grid system of land division found throughout the interior of the United States.

Louisiana's waterways have always been an important means of transportation. The state's vast system of navigable waterways include the Intracoastal Waterway. It is Louisiana's only east-west waterway and canal system and runs some 310 miles (500 km) from Mississippi Sound to the Sabine River. It is part of a larger waterway extending from the Caloosahatchee River in Florida to Brownsville, Texas. The port of New Orleans ranks among the busiest in the country in volume of seaborne freight, while Baton Rouge, farther up the Mississippi River at the head of deep-channel navigation, is important for shipping of petroleum and chemical products, including aluminum and grain.

Louisiana's current constitution, its 11th, was adopted in 1974; it requires a two-thirds majority of each house of the state legislature, and then a majority of the electorate, to amend it. Louisiana has had more constitutions than any other state in the country. The constitution that was adopted in 1921 was Louisiana's 10th in 108 years. It remained in force for more than 50 years, a period during which the state underwent more fundamental change than had occurred in all the preceding years of statehood.

Louisiana has nearly two dozen public and about 10 private institutions of higher education. Louisiana State University (LSU; 1853), which is both the land-grant (land-grant college) and the arts and sciences university, is the keystone of the state system of higher education, with campuses in Baton Rouge, Eunice, Shreveport, and Alexandria. Its former campus, in New Orleans, has become the University of New Orleans (1856). Louisiana Tech University (1894), in Ruston, and the University of Louisiana at Monroe (Louisiana at Monroe, University of) (1931; university status, 1970) are among the other public universities, many of which grew from junior colleges in the 1930s and '40s. Southern University (1880), in Baton Rouge, with campuses also in Shreveport and New Orleans, is a public historically black institution, as is Grambling State University (1901), in Grambling. Private historically black schools include Dillard (1930) and Xavier (1915; Roman Catholic), both in New Orleans. Among other prominent private institutions in the city are Loyola University (1837; Catholic) and Tulane University (1834). A number of public and private institutions offer online degree programs.

In rural culture and the arts, Louisiana more than holds its own. This is especially evident in the realm of music, whether it be African American song (including the celebrated rural blues), Cajun fiddling at the fais do-dos (country dances held in southern Louisiana), the Creole zydeco tradition, or the community hymn singing of northern Louisiana. The urban jazz style that was taken by New Orleans migrants to Chicago and elsewhere, as well as the Dixieland music played by bands at Preservation Hall in New Orleans, are also hallmarks of Louisiana's cultural heritage.

Since the early 19th century, New Orleans has been a major cultural centre of the United States. Its French Quarter has attracted such artists as John J. Audubon (Audubon, John James), the great wildlife painter, and George Catlin (Catlin, George), noted for his portrayals of the American West, and has been the haunt of writers such as Walt Whitman (Whitman, Walt), Sherwood Anderson (Anderson, Sherwood), and William Faulkner (Faulkner, William). The city has also been home to an opera company, as well as various symphony orchestras since the mid-20th century. Other cities, notably Shreveport, Monroe, Baton Rouge, and Lafayette, have established their own museums and galleries, orchestras, choruses, theatres, and other cultural institutions, especially since the 1930s.

Tourism has developed as an important component of the state's economy, using the appeal of the antebellum past and the attraction of Creole cuisine—a blend of French, Spanish, African American, and Native American dishes. A series of parades and balls culminating in Mardi Gras (Shrove Tuesday) has become a national attraction in New Orleans. There are many public parks and gardens, and the state is advertised as a sportsman's paradise for hunting and fishing.

New Orleans is an important centre for both professional and collegiate sports. Tulane usually fields strong collegiate gridiron football teams, and the city is also home to the National Football League (NFL) Saints team. The Super Bowl NFL championship game has been played on multiple occasions in New Orleans, and the Sugar Bowl of collegiate football is held there annually (generally early in January). New Orleans also has a professional men's basketball team (the Hornets). In Baton Rouge, LSU has long been a powerhouse in both collegiate football and basketball. The state's larger cities also host a number of minor league football, baseball, and ice hockey teams.

In 1762 Louisiana and New Orleans were ceded to Spain by a secret treaty that was to establish nearly four decades of Spanish rule and influence in the area. In 1779 the Spanish wrested Baton Rouge from the British and took all of West Florida, which then extended from the peninsula westward across the Gulf Coast to the Mississippi River. In 1800 the Spanish returned Louisiana to France, and three years later the United States, under the leadership of Pres. Thomas Jefferson (Jefferson, Thomas), bought Louisiana from the French emperor Napoleon I. The Louisiana Purchase, a vast acquisition of land for the country, included New Orleans and much of present-day Louisiana state, as well as most of the territory between the Mississippi River and the Rocky Mountains.

Louisiana was subsequently divided into the Territory of Orleans, which consisted essentially of the state within its present boundaries, and the Territory of Louisiana, which included all the vast area drained by the Mississippi and Missouri (Missouri River) rivers. In 1810 the Territory of Orleans consisted of 77,000 people, and statehood proposals were beginning to be heard. When in 1812 the territory petitioned to enter the union, the eastern region now called the Florida Parishes—where the people had rebelled against the Spanish and established the Republic of West Florida—was included. On April 30, 1812, Louisiana entered the union as the 18th state. Between December 1814 and January 1815, New Orleans was the site of the final battle of the War of 1812 (1812, War of), in which U.S. troops led by Gen. Andrew Jackson (Jackson, Andrew) defeated the British.

An agricultural boom took place, and cotton and sugarcane production expanded. Both crops were cultivated primarily by slaves of African descent, and a wealthy plantation society emerged. Small farmers' opposition to planters was apparent in Louisiana state politics, especially after settlement expanded in the hilly northwestern part of the state. Overall, the planters generally prevailed. Many Louisianans were uncertain about secession in 1860, but the state did join the Confederate States of America in 1861 as one of the original seven states in that union.

Southern Louisiana's separation from the Union was short-lived, and by May 1, 1862, New Orleans was occupied by Union army forces under Gen. Benjamin F. Butler (Butler, Benjamin F). The general, intolerant of the lack of cooperation that he received from some Louisianans in the occupied state, had at least one dissident hanged, his intention being to make local residents see clearly the costs of war. Soon Pres. Abraham Lincoln (Lincoln, Abraham) was encouraging the creation of a pro-U.S. state government in Louisiana so that it could reenter the union. Among the controversial issues was whether to give the state's African Americans the right to vote as part of a reconstructed Louisiana, a decision that Lincoln ultimately approved. Despite much debate and controversy, however, the state failed to rejoin the union until after the war ended. Wartime Louisiana foreshadowed the problems of emancipation and Reconstruction that awaited the rest of the South in the postwar period. In the years immediately following the war, ex-Confederates won control of the state government and instituted policies that severely limited the rights of newly freed slaves. However, with the official advent of Reconstruction in 1867, which brought U.S. control over state political matters, a new constitution was written that protected the political rights of African Americans. Louisiana was finally readmitted into the union in 1868.

Louisiana's economy began to diversify significantly in the late 1800s with the emergence of a large timber industry, which continued as a major part of the state's economy into the 21st century. Extensive lumbering attracted large corporations to Louisiana for three decades following 1890, and the discovery of oil and gas reserves helped to increase industrial development. The conservative political leadership of the state refused to tax the extractive industries heavily, however, and the controversy that ensued helped propel the rise of the left-wing demagogue Huey Long (Long, Huey), who was elected governor and then senator beginning in the late 1920s. Through a ruthless political machine that he tightly controlled, Long dominated virtually every public decision made at the state level until his assassination in 1935.

With the support of the rural areas and the emerging working class, Long's administration raised welfare benefits and educational services and built many new bridges, roads, and hospitals. Long's political allies and his brother, Earl K. Long (elected governor in 1948 and 1956), perpetuated his liberal spending policies, and his legacy of public benefits financed by increased taxation has continued to some extent to the present day.

Since the 1970s Louisiana's economy has often sputtered, a reflection of its overdependence on the oil industry, which has tended to tie the state to boom-and-bust cycles. The state also failed to diversify into other industrial activities as fast as some other Southern states, and its service sector has lacked the dynamism of various neighbouring states on the Gulf Coast. The damage and devastation caused by Hurricane Katrina (Katrina, Hurricane) in August 2005 severely affected the state's economy and infrastructure—notably in southern Louisiana—although oil and gas extraction did rebound relatively quickly. After the disaster, the state began to rebuild and repair the affected areas with support from the federal government and a plethora of local and national organizations. Louisiana also introduced incentives to revitalize tourism, notably in the New Orleans area.

Books on the state's geography include Fred B. Kniffen and Sam Bowers Hilliard, Louisiana: Its Land and People, rev. ed. (1988), a concise cultural geography with maps and illustrations; and Louisiana Writers' Project, Louisiana: A Guide to the State (1941, reprinted 1976), also available in a new revised edition ed. by Harry Hansen (1971), an indispensable survey of life in Louisiana. DeLorme Mapping Company, Louisiana Atlas & Gazetteer (2003), focuses on topography; while Charles Robert Goins and John Michael Caldwell, Historical Atlas of Louisiana (1995), concentrates on historical geography. Glenn R. Conrad (ed.), The Cajuns, 3rd ed. (1983), presents essays on Acadian history and culture in Louisiana. Rudolf Heberle, The Labor Force in Louisiana (1948), provides a benchmark from which to study the state's industrial development. Roger W. Shugg, Origins of Class Struggle in Louisiana: A Social History of White Farmers and Laborers During Slavery and After, 1840–1875 (1939, reissued 1968), is a classic treatment of the political process from 1812 to the 1880s. James Bolner (ed.), Louisiana Politics: Festival in a Labyrinth (1982), highlights the structure and practice of Louisiana's government. Mark T. Carleton, Perry H. Howard, and Joseph B. Parker (comps.), Readings in Louisiana Politics, 2nd ed. (1988), provides classic statements of social, economic, and political history with accounts of developments from colonial status onward. Perry H. Howard, Political Tendencies in Louisiana, rev. and expanded ed. (1971), is a historical examination of social structure and voting behaviour. Peyton McCrary, Abraham Lincoln and Reconstruction: The Louisiana Experiment (1978), provides an excellent account of the state's conflicts during the American Civil War. T. Harry Williams, Huey Long (1969, reissued 1996), is a fascinating and sympathetic biography of the politician.Overviews of the state's history can be found in Alcée Fortier, A History of Louisiana, 4 vol. (1904), a classic; Joe Gray Taylor, Louisiana: A History, rev. ed. (1984), an introduction; and Noel Gray, A Short History of Louisiana (1965), which gives attention to the role of the African American community. Glenn R. Conrad (ed.), Readings in Louisiana History (1978), is comprehensive and includes maps and bibliographies. A helpful bibliography is Light Townsend Cummins and Glen Jeansonne (eds.), A Guide to the History of Louisiana (1982). Continuing scholarly research is presented in Louisiana History (quarterly). Adam Fairclough, Race and Democracy: The Civil Rights Struggle in Louisiana, 1915–1972 (1995), provides much new material on the civil rights movement in Louisiana.Robert J. Norrell