Early on in its decades-long run as a weekly magazine, LIFE turned its eye toward always-enticing, ever-vivid New Orleans and that great city's signature annual event: Mardi Gras. In February, 1938, editors sent photographer William Vandivert to the Big Easy to chronicle the carnival, and to show LIFE's readers how one American city — in so many ways a Caribbean, as opposed to a purely Southern, town — maintained a centuries-old tradition of refined debauchery and unalloyed fun in the midst of the Great Depression.
The story that ran in the March 14, 1938, issue of LIFE, alongside some of Vandivert's photographs, was interesting enough, in its own way. Titled "LIFE goes to America's Most Famous Party," the five-page feature focused almost exclusively on the aristocratic Comus Ball, and the pomp and ceremony that attends the crowning of the ball's king and queen.
In fact, in 1938, LIFE was invited to the Comus Ball — "to photograph it," the magazine gently boasted to its readers, "for the press for the first and only time in its 81 years."
But Bill Vandivert was in New Orleans for more than a few days and nights in the late winter of 1938, and he made hundreds of photographs — far more interesting photographs, it turns out, than those that ran in the magazine — on the crowded, chaotic streets and boulevards of that singular town.
Here, in tribute to the undying spirit of the Crescent City, and to celebrate the ancient festival of carnival (from Latin, carne vale, or "farewell to meat") that traditionally marks the beginning of the Christian observance of Lent, LIFE.com offers a gallery of those previously unpublished Vandivert photos: pictures of men, women and children happily caught up in the whirlwind of Mardi Gras, in a vanished New Orleans that feels at once ghostly and somehow inimitably, intensely alive.
Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter at @LizabethRonk.