Mardi Gras comes as the French term for the more traditional American term, Fat Tuesday or Shrove Tuesday - and is the Tuesday that comes before Ash Wednesday.
The origin of Fat Tuesday comes on the last night of eating rich and fatty foods before preparing for the Lenten season - which is a time for fasting in Catholic and other religions, thus the name.
Americans started celebrating Mardi Gras way back in the 1800s. But it was not until 1872 that cue krewes, parades, masks and costumes became part of the event.
This 2012, Fat Tuesday falls on February 21, and parties are now underway. So get your Mardi Gras costumes on and celebrate. Happy Mardi Gras!