The Battle of Olympia was a military encounter in and around the city of Olympia in July and August of 1925 between the Imperial Japanese Army and the United States Army, resulting in the capture of the city by Japanese soldiers in late July but their forced withdrawal in late August after being unable to successfully convey their success into a more concerted attack on nearby Tacoma.
Due to the relative lack of air or sea support, the Japanese were forced to fight an American enemy that had the advantage of both seapower in Puget Sound as well as airplanes attack from the nearby Boeing Airfields in Tacoma, where five fighter planes were being built per day. The Japanese managed to surprise American planners by attacking Olympia first, which lay on the western flank of the US 8th Army's positions in the Nisqually Valley, but were unable at successfully reach Tacoma or its outlying communities due to heavy fortifications along the river. On August 14, an American counterattack dislodged the Japanese, who themselves launched a counteroffensive August 17-20, managing to briefly drive the Americans back towards Tacoma. However, Japanese efforts to significantly capitalize on this surprising gain failed and they retreated back along the Chehalis River towards the coast and towards Oregon, splitting the army in two in a widely criticized move that eventually allowed the Americans a victory at Monticello in early September.