Indians of the Nisqually tribe attacked white settlers in the area on October 29, 1855, as a result of their dissatisfaction with the Treaty of Medicine Creek that had been imposed on them the previous year, particularly angered that their assigned reservation curtailed the traditional fishing economy. The fort was headquarters for the U.S. 9th Infantry Regiment during this "Indian War" of 1855-56.
On October 29, 1855, Nisqually Indians attacked white settlers in protest of the Treaty of Medicine Creek that year. They were particularly upset by the restriction on their traditional fishing economy to a new reservation. The fort served as headquarters for U.S. forces during this conflict known as "The Indian War" from 1855 to 1856.