Fort Walla Walla protected a vast area of the Northwest during its years of operation. Troops from the fort fought in the Steptoe Expedition, Wright Expedition, Modoc War, and Bannock War. Regiments stationed there included the 9th United States Infantry, 21st Infantry, 1st Cavalry, 2nd Cavalry, 9th Cavalry, 14th Cavalry, 1st Oregon Volunteer Cavalry, 30th Battery Field Art., 4th Calvalry, 2nd Infantry, and 146th Field Art. W.W.I. soldiers killed in the various Indian campaigns are buried in the Old Military Cemetery there.