NOLA was probably majority nonwhite for most of its history. I know that, right before the civil war, the majority of the population was either enslaved or "free persons of color." Thanks to a large influx of Irish, Italian, and German immigrants, however, it became a majority white city after the Civil War, and would remain so until the 1970s. I once dated a girl from NOLA of Greek ancestry who told me that their was a sizeable Greek community on the East Side of the city until white flight hit the nabe in the late 70s/early 80s.
BTW: Your home state of Mississippi was majority black until the late 1940s. South Carolina was majority black when Pitchfork Ben Tilman was at the peak of his power at the turn of the last century.
That is correct about Mississippi. They all went to Detriot and Chicago for work between the World Wars....with a fair number of whites
NOLA was majority white from General Butler's visit until 1974....as Jefferson parish grew.