Fort Assiniboine, established by act of Congress in May 1878 as a guardian of Montana's frontier, stood on a high site on Beaver Creek selected by Lt. Colonel Brooks, who superintended its million-dollar construction. The fort took its name from the neighboring Assiniboine (sic) Indians tribe. Infantry and cavalry detachments were stationed there to hold off marauding Indians, including Sitting Bull's hostile Sioux, but after the fort was completed they never took part in a single engagement. The post instead became one of four important forts nominally guarding the border. General Pershing, then a young lieutenant, served there in the nineties. After the Tenth Cavalry was ordered to Cuba in 1898, Fort Assiniboine was practically abandoned, and in 1911 President Taft signed the bill abolishing the largest military reservation in the United States.