Louisiana is the only state in which Mardi Gras is a legal holiday. However, elaborate carnival festivities draw crowds in other parts of the United States during the Mardi Gras season as well, including Alabama and Mississippi. Each region has its own events and traditions. The first American Mardi Gras took place on March 3, 1699, when French explorers Pierre Le Moyne d’Iberville and Sieur de Bienville landed near present-day New Orleans, Louisiana. They held a small celebration and dubbed their landing spot Point du Mardi Gras.

Source: History