Fort Gibson is a historic military site next to the modern city of Fort Gibson, in Muskogee County Oklahoma. It guarded the American frontier in Indian Territory from 1824 to 1888. When it was constructed, the fort was farther west than any other military post in the United States. It formed part of the north-south chain of forts that was intended to maintain peace on the frontier of the American West and to protect the southwestern border of the Louisiana Purchase.
