Dictionary.net

First known to the whites as residing east of the Mississippi. They early joined the English against the French and in 1739 entered into friendly relations with General Oglethorpe. In 1765 their head men with those of the Choctaws met Governor George Johnson in a congress at Mobile and established friendly trade relations. By the treaty of 1786 their territory was fixed with a boundary at the Ohio on the north and extended down into what is now Mississippi. They continued friendly with the whites during Indian hostilities and aided them against the Creeks in 1793. By treaties in 1805, 1816 and 1818 they ceded all their lands east of the Mississippi, some of the tribe having previously, about the year 1800, migrated to the Arkansas. In 1832 and 1834 the Chickasaws ceded the remainder of their lands and migrated to the territory of the Choctaws, with whom they lived under one government until 1855, when they were granted a political separation. Early in the Civil War they took sides with the South.