From stately oak-lined avenues to raunchy displays in the French Quarter, New Orleans let loose with a Mardi Gras party as parades rolled and revelers frolicked amid showers of beads, trinkets and music.

The French Quarter began to fill with costumed revelers soon after dawn. Some people hadn't stopped drinking since Monday's Lundi Gras prequel to Mardi Gras.

Wearing a bright orange wig, a purple mask and green shoes, New Orleans resident Charlotte Hamrick walked along the main avenue of Canal Street to meet friends.

"I'll be in the French Quarter all day," Hamrick said. "I don't even go to the parades. I love to take pictures of all the costumes and just be with my friends. It's so fun."

Across the globe, people dressed up in elaborate costumes and partied the day away. In Rio de Janeiro, an estimated 850,000 tourists joined the city's massive five-day blowout. Meanwhile, the Portuguese, who have suffered deeply in Europe's debt crisis, defied a government appeal to keep working.

In New Orleans, Brittany Davies was struggling through the early morning hours. Still feeling the effects of heavy drinking from the night before, her friends had her out again early Tuesday.

"They're torturing me," Davies joked. "But I'll be OK after a bloody mary."

The predominantly African-American Zulu krewe was the first major parade to hit the streets, shortly after 8 a.m. Most krewe members were in the traditional black-face makeup and the Afro wigs Zulu riders have sported for decades.

In the oak-lined Garden District, clarinetist Pete Fountain prepared to lead his Half-Fast Walking Club on its annual march down historic St. Charles Avenue.

Fountain, 82, gave a thumbs up to start off and his band launched into "When The Saints Come Marching In" as they rounded the corner onto the avenue of 19th century mansions. It was the 52nd time that Fountain's group has paraded for Mardi Gras. This year, the group wore bright yellow suits and matching pork pie hats for its theme, "Follow the Yellow Brick Road."

In the Quarter, Joshua Westbrook had been on Bourbon Street drinking since Monday afternoon. His eyes were tired Tuesday morning but he was determined to see Mardi Gras through.

"I'm struggling, but I'm going to push through it," he said.

Wearing a purple wig, New Orleans resident Juli Shipley carried a gallon (almost 4 liters) of booze down Bourbon Street and filled her friends' cups when they got low. "We're going to wander all day and people-watch," Shipley said. "That's the best part of Mardi Gras _ the costumes. They're amazing."

Partygoers were dressed as Wizard of Oz characters Dorothy and the Wicked Witch, bags of popcorn, pirates, super heroes, clowns, jesters, princesses and lots of homemade costumes with the traditional Mardi Gras colors of purple, green and gold.

Tom White, 46, clad in a pink tutu, bicycled down the avenue with his wife, Allison, on their way to the French Quarter. "I'm the pink fairy this year," he said. "Costuming is the real fun of Mardi Gras. I'm not too creative but when you weigh 200 pounds and put on a tutu people still take your picture."

His wife was not in costume. "He's disgraced the family enough," she said.

The celebration arrived in Louisiana in 1682 when the explorer LaSalle and his party stopped at a place they called Bayou Mardi Gras south of New Orleans to celebrate. The site is now lost to history.

The end of Mardi Gras gives way to the beginning of Lent, the period of fasting and repentance before Easter Sunday.