Among the men dressed in pink baby-doll pajamas or leather loincloths and the women flashing glimpses of flesh for beads were some whose costumes had political themes. Louisiana voters don't head to the polls until Saturday, so many let their costumes make political statements on a day when 24 other states were holding presidential primaries and caucuses.
Kim Disselliss, 49, simply taped a sign to her back showing Sen. Clinton dressed as George Washington and reading, "Monica Lewinsky's X-Boyfriend's Wife for President. 2 for 1 Sale."
Mardi Gras - also known as Fat Tuesday - is the end to the pre-Lenten Carnival season. The celebration characterized by family friendly parades uptown and in the suburbs - and by heavy drinking and lots of near-nudity in the French Quarter - ends 12 days of parades and parties.
Temperatures were expected to rise to about the record of 81 degrees in New Orleans, an indicator that flesh-flashing in the bawdy French Quarter was likely to be greater than usual. Crowds that had begun staking out spots on the parade routes as early as Friday night spent the day collecting beads and other trinkets thrown from floats.
The celebration appears to have bounced back strongly since Katrina flooded more than 80 percent of the city. Mardi Gras crowd estimates hovered around 1 million in the years before Katrina, and the crowd reached about 800,000 last year. This year, however, some worried turnout would be lighter because the celebration fell so early.
Kevin Kelly, who lives on the parade route, said the crowds did seem quieter. It was too early for college students on spring break to join the party, Kelly pointed out.
"And frankly, it's a good thing," Kelly said. "The city smells better without a bunch of drunken kids using every doorway as a toilet."
Clarinetist Pete Fountain, dressed in a tunic as one of King Arthur's knights, looked frail but happy Tuesday morning as he led 100 members of his Half-Fast Walking Club onto Uptown streets in what has become the city's unofficial opening of Mardi Gras.
"Oh, I'm feeling fine. You always feel fine on Mardi Gras," said Fountain, 77. He's had health problems since Hurricane Katrina, but still plays two days a week at a Gulf Coast casino.
While the walking club was on its way, floats of the Zulu parade headed for their starting point. Zulu, the black community's oldest parade, was followed by the Rex parade, with businessman John E. Koerner III reigning as Rex, King of Carnival and Monarch of Merriment.
In Cajun country, costumed riders on horseback set out on their annual Courir du Mardi Gras, a town-to-town celebration. Hundreds of people registered for the Courir de Mardi Gras in Eunice, a bayou community 150 miles west of New Orleans. Hundreds were on horseback and scores of others rode along in pickup trucks or on flatbed trailers.
"It's just heritage. It's Louisiana. We're crazy," said Courir participant Cody Granger, 24, wearing what looked like surgical scrubs decorated with the New Orleans Saints' logo.
Sporadic violence has marred the celebration in New Orleans. At least nine people had been wounded by gunshots, six of them on Saturday. Shots were fired Tuesday near a parade route, but no one was injured and a suspect was quickly arrested, police said.
Police said 1,100 officers, state troopers and National Guardsmen have been positioned along parade routes since the season began.
Still, most partygoers were undeterred. The smell of charcoal and sizzling meat accompanied the sounds of people urging float riders to "throw me something," and band music played as cooks prepared everything from burgers to crawfish along the parade route.
"We had beer for breakfast, but we're making it a side dish now," David James said. "You have to pace yourself when you get here at dawn."
Associated Press Writers Mary Foster, Becky Bohrer and Stacey Plaisance contributed to this report.