I'm not sure if anyone else has made a connection between the Mardi Gras Indians and the Jonkonnu {John Canoe}celebrations by 18th century {and probably earlier} African Americans in the South. Both feature masking and promanading in the streets. Both seem to be a blend of West African, Caribbean, and English traditions.

See this description of the early Mardi Gras Indian costumes from the Grateful Dead page whose link was provided earlier:

Reg Johnsey came up with this explanation {for the reference to chicken wire in the song "Iko Iko":
The way country people celebrated Carnivale/Mardis Gras was to make conical masks out of chicken wire and decorate them, wearing them with costumes festooned with strips of cloth. So, the references to fixing someone's chicken wire sounds like a joking threat to mess up their masks, since part of the battle was how good the costumes were."

And see this excerpt from this website:
Pulse Planet: Jonkonnu

"Jonkonnu drumming and singing
We're in New Bern, North Carolina where musicians and dancers, dressed in feathers and brightly colored rags make their way down the street from house to house. They're observing a frenetic ritual that blends elements of West African, Caribbean, and English tradition. I'm Jim Metzner, and this is the Pulse of the Planet. In the celebration known as Jonkonnu , revelers dance to the sound of a square drum called a "gumba box." Slaves probably brought it to North Carolina from Jamaica around the year 1770. Historian Simon Spalding says that like the drum, many aspects of this festival can be traced back through time. However, the origin of the word "Jonkonnu" itself remains a mystery.

"There are literally dozens of possible derivations in several African languages that have to do with festival celebrations. It was also suggested that there was someone named John Canoe or John Cooner who was a slave trader on the coast of Africa, and that ís who it was named for - because in some versions Jonkonnu is a person, in other cases it's the description of the whole celebration."

It's easy to hear the Afro-Caribbean influence of Jonkonnu music. But other important elements of the the celebration, like the prominent figure of a Ragman, harken back to English customs.

"Jonkonnu is often held in the Caribbean, and I'm told in Guyana as well, on Boxing Day, which is a very traditional English holiday, the day after Christmas. On Boxing Day in many parts of England men dance in the streets wearing ragman clothes like this - trousers and jackets or shirts that have these strips of cloth - and often carrying wooden swords. In Jonkonnu in Jamaica, and here in North Carolina, you have the exact same kinds of clothing and you also have the ragman often carrying a wooden stick."

-snip-

BTW, I'm not an adherent of the view that Jonkonnu comes from the name of a slave trader named "John Canoe" . Why would enslaved people be celebrating the memory of a slave trader? I believe that's a bogus folk etymological {if that's such a word} explanation. I'd suggest looking for the word or similar words in African cultures that celebrate or honor spirits and ancestors through masking. One example I'd promote is the Egungun celebrations in Nigeria.