xkcd

The word “Arkansas” came from the Quapaw Indians, by way of early French explorers. ... The state’s name has been spelled several ways throughout history. In Marquette and Joliet’s Journal of 1673, the Indian name is spelled AKANSEA. In LaSalle’s map a few years later, it’s spelled ACANSA. A map based on the journey of La Harpe in 1718-1722 refers to the river as the ARKANSAS and to the Indians as LES AKANSAS. In about 1811, Captain Zebulon Pike, a noted explorer, spelled it ARKANSAW.