USA TODAY -- Mardi Gras, French for Fat Tuesday, is synonymous with revelry before Ash Wednesday, the first day of Lent. Festivities begin on Jan. 6, known as the Feast of the Epiphany, Twelfth Night or Three Kings' Day.
Mardi Gras celebrations date to Medieval Europe. In New Orleans, Mardi Gras celebrations grew out of Catholicism but also wove in "French celebrations, African music and the masquerade tradition," says Karen Leathem, museum historian for the Louisiana State Museum in New Orleans.
In New Orleans, the first written record of Mardi Gras celebrations is from 1699 with gatherings around a campfire. By the 1730s, much of our modern-day traditions had started: People wore masks in processions, with slaves carrying flambeaux, or torches, Leathem said.
In 1875, Fat Tuesday became an official holiday in Louisiana.
The first parade in New Orleans was organized in 1857 by the Mistick Krewe of Comus.
A krewe is a "fanciful spelling of crew" and an organization that puts on festivities for Mardi Gras, says Mark Romig, president and CEO of New Orleans Tourism Marketing Corp.
Krewes name a royal court, including a king and queen, who ride the floats and preside over the balls.
"It's almost a spoof on European aristocracy," Hardy says. "It's all in fun, but we take our fun very seriously."
Mardi Gras Indians
Mardi Gras Indians are African Americans who dress in elaborate headdresses and costumes for the Carnival celebrations.
The origins of the Mardi Gras Indians are contested. One theory is the Mardi Gras tradition grew out of black people's respect for Native Americans, who took in runaway slaves.
It's also possible the tradition is influenced by William "Buffalo Bill" Cody's Wild West show in 1884, and had nothing to do with indigenous Native Americans, Hardy says.
"Our Mardi Gras Indians kind of copied the headdresses of those Indians," Hardy says. He points out that one of the oldest Mardi Gras Indian tribes is called Creole Wild West.
Mardi Gras Indian celebrations do not take place on official parade routes but in the backstreet neighborhoods, Hardy says.
Float riders often toss out "throws" or inexpensive trinkets to the crowd, including strings of beads. These beads used to be made of glass, but today most are plastic and the most sought-after light up with LED lights, Leathem says.
Purple, green and gold are the traditional Mardi Gras colors. The Krewe of Rex chose these colors in 1872 to honor a visiting Russian grand duke, whose house colors were purple, green and gold, according to the website Mardi Gras New Orleans.
Later, the Rex krewe assigned meanings to each color. Purple stands for justice, green for faith and gold for power.
Today's mask-wearing comes from the European masquerade tradition. Masking was a way for people to "escape society and class constraints," according to Mardi Gras New Orleans.
"You could be anyone you wanted to pretend to be," Hardy says. "Anonymity is a key ingredient."
King cake is a ring of dough, cinnamon-streaked, filled or plain, and topped with sugar in the traditional colors of Mardi Gras - purple, green and gold. Inside the cake is a plastic baby meant to represent Jesus.
In the late 19th century, the Twelfth Night Revelers krewe started the custom of hiding a bean inside a cake. The person who ended up with the bean would be crowned king or queen of the ball, reports NPR.
The tradition of a plastic baby in the cake started in the 1930s. Donald Entringer, president of McKenzie's Bakeries, was asked to make king cakes for a krewe.
He found some pink plastic babies in a shop in New Orleans' French Quarter and got permission from the health department to bake them into his cakes, The Times-Pecayune reports.