The first Mardi Gras was February 27, 1827 in New Orleans, Louisiana. Early French settlers practiced Mardi Gras in other areas before New Orleans but it by the end of the 17th century Spanish Governors put an end to the celebration. AFter Louisiana became a state the residents of New Orleans managed to have the ban on wearing masks and dancing/partying in the streets.
The original Mardi Gras was a group of students, who had returned from school in Paris, wore masks and costumes and danced through the streets on the last day of Carnival season. Also known as Fat Tuesday because it was the day before Ash Wednesday.
Ten years later in 1837 the first "organized' Mardi Gras parade was started. It was reported in 1839 that there was only one float but people marveled at the parade and it was considered a successful event.
In 1872 Grand Duke Alexis Romanoff from Russia attended the parade. It was through his presence and influence that the traditional colors of Mardi Gras were adopted. Purple as the symbol of Justice, green as the symbol of faith and gold as the symbol of power.