The history of slavery in the territory currently known as Louisiana began before its settlement by Europeans, as Native Americans also reduced captured enemies to the status of slaves. Following Robert Cavelier de La Salle establishing the French claim to the territory, and the introduction of the name Louisiana, the French developed their first settlements at Natchitoches (1713) and New Orleans (1718), and introduced slavery. The institution was maintained by the Spanish (1763–1800) when the area was known as new Spain, by the French when they returned (1800--1803) and by the United States, following the Louisiana Purchase of 1803.
When France sold the Louisiana territory to the United States in 1803, it was soon accepted that enslaved Africans could be brought there as easily as they were brought to neighboring Mississippi though it violated U.S. law to do so. Though Louisiana was, at the start of the 19th century, a small producer of sugar with a relatively small number of slaves, it soon became a big sugar producer after plantation owners purchased enslaved people who had been transported from Africa and then to South Carolina before being sold in Louisiana where plantation owners forced the captive labor to work at no pay on their growing sugar cane plantations. Despite demands by United States Rep. James Hillhouse and by the pamphleteer Thomas Paine to enforce existing federal law against slavery in the newly acquired territory, slavery prevailed because it was the source of great profits and the lowest cost labor. The last Spanish governor of the Louisiana territory wrote that "Truly, it is impossible for lower Louisiana to get along without slaves" and with the use of slaves, the colony had been "making great strides toward prosperity and wealth." Forced slave labor was needed, said William C. C. Claiborne, Louisiana's first United States governor, because unforced white laborers "cannot be had in this unhealthy climate." Hugh Thomas wrote that Claiborne was unable to enforce the abolition of trafficking in human beings where he was charged with doing so in Louisiana.
The demand for slavery increased among U.S. settlers in Louisiana and other parts of the Deep South after the invention of the cotton gin (1793) and the Louisiana Purchase (1803). The cotton gin allowed the processing of short-staple cotton, which thrived in the upland areas. It made possible a new commodity crop in northern Louisiana, although sugar cane continued to be predominant in the southern part of the territory. The northern area of the state became another outpost for the "Cotton Empire", which soon encompassed neighboring states, such as Arkansas, Mississippi, Alabama, Georgia and Texas.
The Mississippi River delta area around New Orleans created the ideal alluvial soil necessary for the growing of sugar cane. Sugar was the prime export of Louisiana during the antebellum period.
In 1811, the largest slave revolt in American history took place outside New Orleans, as slaves rebelled against the brutal work regimens of sugar plantations. The 1811 German Coast Uprising ended with white militias hunting down black slaves, lopping off their heads, and placing the piked heads on the levees.
Slavery was officially abolished by the Thirteenth Amendment which took effect on December 18, 1865. Slavery had been theoretically abolished by President Abraham Lincoln's Emancipation Proclamation which proclaimed, in 1863, that slaves located in territories that were in rebellion from the United States were free. In some areas, slaves left their plantations to seek Union lines for freedom. If located too far away, they were often held in servitude until the US gained control of the South.
A number of notable leaders were associated with Louisiana during the Civil War, including some of the Confederate Army's senior ranking generals, as well as several men who led brigades and divisions. Antebellum Louisiana residents P.G.T. Beauregard, Braxton Bragg, and Richard Taylor (son of former US President Zachary Taylor) all commanded significant independent armies during the war. Taylor's forces were among the last active Confederate armies in the field when the war concluded.