Mardi Gras as we know it today originated in Mobile after the Civil War as a way to bring some joy back to the people of the region suffering through the loss of family and harsh economic times.
In theory, it’s for everyone. In practice, it has a history of segregation just as much as any other institution in the South. The Colored Carnival Association was brought into being in Mobile in 1938 as a way for African-Americans to have their own Mardi Gras celebration. That eventually became MAMGA, the Mobile Area Mardi Gras Association.
Unfortunately, Mardi Gras in Mobile, New Orleans, and the rest of the Gulf South is still a very segregated institution.