Louisiana itself became a state in 1812, well before the territories to its east (including Florida); most of the remaining lands of the Louisiana Purchase had to wait quite a bit longer. For nearly a decade, Louisiana was the westernmost state in the Union.
The traditional couple and group dances brought to New Orleans by Europeans are now preserved mainly by their descendants as Cajun music and dance. The related style of dancing known as Zydeco apparently originated in black communities. Its "classic" form is a leisurely looking (but difficult to learn) 8-beat shuffle, but the many (!) YouTube videos show mainly variants of 6- or 8-beat swing (rooted in Lindy Hop).