Choctaw is an American Indian tribe located in the banks of the Mississippi river. It was the first land cession treaty signed between US and the Choctaw nation.
Thus Choctaw is absorbed as a non-ethnic US territory with most of the Choctaw tribes who still reside there and gained US citizenship.
Choctaw land which was surrendered was called the ‘Dancing Rabbit creek’ and hence the treaty was signed after that name which recognized the Choctaw people as US citizens.