This section is from "The American Cyclopaedia", by George Ripley And Charles A. Dana. Also available from Amazon: The New American Cyclopędia. 16 volumes complete..
Arkansas, the name given by the Algonquins to the Ouquapas, a tribe of Indians of the Dakota family. According to Gravier, a Jesuit missionary in Illinois about the year 1700, the Arkansas had previously resided on the Ohio river, whence after a long struggle they were driven down the Mississippi by the Illinois and their allies. This corresponds with the tradition of the Lenni, another Algonquin tribe, as to the Allegewi or Alleghans; and as early French writers use indifferently the term Alkansas or Akansas, the suspicion increases as to their identity. They comprised several divisions known as the Quappas or Kappas, Dogin-ga, Toriman, and Osotteouez or Sothouis. One division, called by the Algonquins Mitchiga-mias, removed to the country of the Illinois, but subsequently returned. The Arkansas were first visited by Marquette, and from his time were always friendly to the French, welcoming La Salle and Tonti, as well as the survivors of La Salle's last expedition. They refused to join the Natchez against the French, and nearly exterminated the Yazoos, who had massacred the French among them. They were at this time a powerful tribe, able in 1740 to send out 400 warriors, but they soon lost by smallpox and other diseases.
The remnant, now called Quapaws, are in the Indian territory west of their former country, and number only 200.