In pop culture, it seems like the city of New Orleans is just as famous for the supernatural and spooky as Salem, and for whatever reason, vampires are a large part of its mythos. From urban legend to the novels of Anne Rice, vampirism seems to play as big a role as voodoo in the collective imagination. I've even read about the "real" vampires in New Orleans, who drink blood for whatever reason. What is the connection between Louisiana and vampirism? Does it have something to do with its French history? Were vampires even a popular legend in France?
The fantastic old cemeteries of New Orleans deserve a word for themselves. On account of the shallow soil all burials are above ground. The wealthy lie in fantastic tombs, whilst less opulent citizens are enclosed in oven-like vaults along the ten-foot-thick brick walls of the necropolis. Of all these grotesque ossuaries, the old St. Louis Cemetery just outside the Vieux Carré is undoubtedly the most interesting. Lafcadio Hearn has written of it movingly & gruesomely somewhere in his “Fantastics”—which, by the way, I must re-read now that I’ve seen N. O.
And I passed with him through the Egyptian gates, and beyond the pylons into the Alley of Cypresses; and he showed me the dwelling- place of the rich in the City of Eternal Sleep,—the ponderous tombs of carven marble, the white angels that mourned in stone, the pale symbols of the urns, and the names inscribed upon tablets of granite in letters of gold. But I said to him: "These things interest me not;—these tombs are but traditions of the wealth once owned by men who dwell now where riches avail nothing and all rest together in the dust."
New Orleans came into the United States in 1803 as part of the Louisiana Purchase. The culture of Louisiana was very distinct from much of the rest of the United States - there was a strong French/Acadian identity, and a Creole culture where racial distinctions existed in bewildering closeness to Northerners, and even after the United States moved in the region remained much of its distinct culture, language, and religion - which in this case involves both Catholicism and the local tradition of rootwork or syncretic indigenous African religion popularly called "voodoo."
I don't want to over-emphasize the prevalence of voodoo; like a lot of folk beliefs and superstitions, it's difficult to track and not reliably recorded, but figures like Marie Laveau (1801-1881) and her daughter of the same name (1827-c. 1862) undeniably added to the local color and legendry of New Orleans.
For the most part, the 19th century New Orleans does not appear to be a primary haven for vampires, however. There are legends of spectral figures and ghosts, and you can buy tourist books full of that kind of tattle, some of them traceable to period accounts and some of them so much make-believe. This shouldn't be really surprising: the vampire (and for that matter, the zombie) hadn't yet taken their fixed form as we know them today - the vampire was popularized by the success of Bram Stoker's Dracula (1897), and the zombie by William Seabrook's The Magic Island (1929) - so while there might have been the odd story of the revenant (animated corpse) or ghost, you don't see a lot of vampires in particular.
About the turn of the century, more attention both scholarly and popular was turned to the weird and supernatural, as well as indigenous folklore practices. The United States invaded and occupied Haiti from 1915-1934, and the Dominican Republic from 1916-1924; the US took possession of the Danish West Indies in 1917 and renamed them the Virgin Islands, and all of these Caribbean territories had indigenous folk beliefs, "jumbee" and "Vodou" tales that began to titillate the American fancy - and stir interest in the systems of conjure, rootwork, hoodoo, and Louisiana voodoo still prevalent in the United States. Alongside this was genuine scholarship by anthropologists and folklorists like Zora Neale Hurston, who would chronicle many of these practices before they faded from disuse or were commercialized beyond recognition.
Louisiana, and New Orleans in particular, became a focus of popular interest among both pulp-fiction and the occult during the 1920s and 30s. These took the form of stories like "Pledged to the Dead" by Seabury Quinn (Weird Tales Oct 1937), which is a variant on the corpse-bride legend set in the Old St. Louis Cemetery, and Kirk Mashburn's "De Brignac's Lady" (Weird Tales Feb 1933) which is a vampire story and...so on and so forth.
The great old St. Louis Cemetery became a tourist spot, as were the Dueling Oaks and the Vieux Carré, and all the zoning, redistricting, and new development never quite rid New Orleans of that touch of Old World glamour for many. Even today you can see ideas of Louisiana being "different" in media like True Detective (Season 1).
Anne Rice was born in New Orleans, and when she wrote Interview with the Vampire (1973) after the death of her daughter, she set it there - and it clicked, becoming an international bestseller, spawning sequels, and eventually a very successful film adaptation in 1994. Rice's Vampire "trilogy" (soon to expand) were primary inspirations for the tabletop roleplaying game Vampire: the Masquerade (1991), which would include New Orleans among its many settings. More generally, Anne Rice's take on vampires as sensual, powerful, emotional immortals who strayed between power-tripping and existential despair hit a chord, and strongly influenced subsequent depictions in, for example, the Southern Vampire Mysteries (2001-2013) of Charlaine Harris, which in turn inspired the popular television series True Blood (2008-2014).
There are lots of lesser influences I'm leaving out; Anne Rice wasn't the only New Orleans native to write a revenant or vampire story set in the Big Easy, and it's hard to say what the "first" was - it was an international port city with a lot of cultural cachet, and myriad influences - serial killers like the Axeman and French/Acadian legends like the loup-garou all added to the general milieu that gave birth, eventually, to the idea of New Orleans in particular and Louisiana in general as vampire country - or voodoo country, ghost country, etc. - which some folks have capitalized on the same way contemporary Salem capitalizes on the Witch Trials, and ensconced firmly in Hollywood legend by innumerable horror movies set in or around New Orleans.
New Orleans isn't really historically a center of vampiric so much as it's historically a center of mysticism.
To start, I want to address the word 'occult'. Occult is a word that evokes a lot of different things to a lot of different people; candles mounted on skulls, pentagrams, paganism, witchcraft, voodoo dolls, tarot; all of this and none of this is occult.
Occult shares an etymological root with the word "occlude" (EDIT: I'm wrong here; different base words, despite the similar prefixes); it means secret or hidden, rather than mystical. Classical religions such as Hellenism would use the word 'occult' to refer to interior ritual; those parts of the faith practiced by the priesthood away from the lay faithful. It wasn't until Christianity became entrenched in Europe that the word 'occult' began to take on its more mystical meaning. Missionaries would use the word to refer to any religious practices of other religions, including Jewish and Muslim during the Inquisition, but most especially native pagan faiths. The war of information, as Christians sought to eradicate these faiths, and they rapidly became more secretive in response, was definitively won by the missionaries. Soon, the word 'occult' meant any blasphemous practice, from witchcraft (which, in the Christian mind was the nebulous bridge between Satanic powers and pagan faiths) to the practices of splinter sects of Christianity, such as Catharism.
You've probably already guessed where I'm going, but in case you haven't, New Orleans is famous for being one of the major centers of the Voodoo faith, which is a syncretic fusion of Catholicism and a West African faith called Vodun, perhaps the purest expression of the extremely interesting and dynamic Creole culture formed by French settlers and West African slaves and Freemen, with bits of Native American culture and a sprinkling from Spanish traders sprinkled in.
Creole Voodoo actually originated in Haiti, as slave owners were required by law to Christianize their slaves shortly after arrival. As they incorporated Catholic elements into their ancestral faith, they also slowly began to spread the faith throughout the Caribbean, though it didn't take root anywhere as strongly as in New Orleans and Louisiana. Enter the hay day of the city's occult reputation: Marie Laveau. Socially influential for her day, Laveau was a hairdresser by trade who was apparently quite a skilled gossip. People would patronize her for advice, paying her for suggestions, and she would give that advice with more knowledge than she really should have. Reportedly, even wealthy white socialites would utilize this service, not just the black community.
Being heavily involved in the traditional Voodoo spiritualism, Laveau went on to codify New Orleans Voodoo (which is different from Haitian Voodoo and Vodun in a similar way to how Protestant Christianity is different from Eastern Orthodox, and, arguably, how both are different from Judaism). She created a much more formal organization for New Orleans Voodoo, including formal ritual sites, formal rites, and codified a more formal theology.
These ritual sites are most important to New Orleans's legacy as a city of the occult. Non-faithful would sneak into the woods around one of these, Bayou St. John, and watch the rituals from afar, returning to the city and exaggerating what they witnessed. Why did this lead to a reputation for vampirism?
Here's where we circle back to my very boring description of the word 'occult.' Anything vaguely mystic and foreign to western religious practices has a tendency to be lumped under that one umbrella term, and it's very easy for Judeo-Christian raised Americans to conflate Zen meditation practices, Shao-Lin martial arts, Vodun spirit summoning, and any other practice that subtly hints at the subtly supernatural. Anne Rice isn't the only novelist to take advantage; somehow, Translyvania is now also famous for its werewolves in addition to being the ancestral stronghold of Count Dracula, as another example. The occult reputation of the subtle, Cajun accents and French Colonial architecture makes the perfect backdrop for that type of story.
EDIT: To sum up, as I didn't do the best job summarizing, when vampires captured the American zeitgeist, when selecting a home city for them to be focused upon, New Orleans having a reputation for the occult made it a natural locale, despite vampires having nothing to do with the Voodoo religion from which that reputation originally derived.