Fort Walla Walla is a United States Army fort located in Walla Walla, Washington. The first Fort Walla Walla was established July 1856, by Lieutenant Colonel Edward Steptoe, 9th Infantry Regiment. A second Fort Walla Walla was occupied September 23, 1856. The third military Fort Walla Walla was built adjoining Steptoeville, now Walla Walla, Washington, a community that had grown up around the second fort. The third and permanent Fort Walla Walla was established in 1858. An Executive Order on May 7, 1859 declared the fort a military reservation containing 640 acres and 640 acres each of hay and timber reserves. On September 28, 1910 soldiers from the 1st Cavalry lowered the flag closing the fort. In 1917, the fort briefly reopened to train men of the First Battalion Washington Field Artillery in support of action in World War I. In 1921, the fort and property were turned over to the Veterans Administration where 15 original buildings from the military era remain. Today, the complex contains a park, a museum, and the Jonathan M.