Pope Gregory XIII add the event to the Gregorian calendar in 1582 on the day before Ash Wednesday, which Lent, the 40 days of fasting and prayer leading up to Easter Sunday.
Mardi Gras arrived in North America as a French Catholic tradition with the Le Moyne brothers, Pierre Le Moyne d’Iberville and Jean-Baptiste Le Moyne de Bienville, in the late 17th century, when King Louis XIV sent the pair to defend France’s claim on the territory of Louisiane, which included what are now the U.S. states of Alabama, Mississippi, Louisiana and part of eastern Texas. Lawmakers in Louisiana made Mardi Gras a legal state holiday in 1875. It is still observed in parts of the state and is also a state holiday in Alabama and Florida.
Mardi Gras is French for "Let the good times roll" or "Fat Tuesday", reflecting the practice of the last night of eating richer, fatty foods before the ritual fasting of the Lenten season. While not observed nationally throughout the United States, a number of traditionally ethnic French cities and regions in the country have notable celebrations.
This occasion refers to events of the Carnival celebrations, beginning on or after the Christian feasts of the Epiphany (Three King’s Day) and culminating on the day before Ash Wednesday. International names for Mardi Gras include: Martes de Carnaval in Mexico, Fastan in Sweden, Martedi Grasso in Italy, J’Ouvert in Trinidad, and Karneval in Germany. Mardi Gras is also known as "Shrove Tuesday", which is derived from the word shrive, meaning "confess".
New Orleans held its first Mardi Gras parade in 1837, but was not the first American city to host a parade for the occasion. That was Mobile, Alabama. Louisiana is where the celebration originated in North America, though, and for that we can thank France for sending the Le Moyne brothers in 1699. Happy Mardi Gras!
In 2017 Mardi Gras or Shrove Tuesday in USA falls on February 28.