E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A word borrowed from the Algonquin, meaning one who acts and thinks independently. In Eliots Indian Bible the word centurion in the Acts is rendered mugwump. Those who refuse to follow the dictum of a caucus are called in the United States mugwumps. The chief of the Indians of Esopus is entitled the Mugwump. Turncoats are mugwumps, and all political Pharisees whose party vote cannot be relied on.
I suppose I am a political mugwump, said the Englishman. Not yet, replied Mr. Reed. You will be when &ygrave;ou have returned to your allegiance.The Liverpool Echo, July 19th, 1836.