From 1820 to 1827, the nation’s largest and most westerly military post occupied this site, the earlier scene of Lewis and Clark’s Council Bluff. In late 1819, troops under Colonel Henry Atkinson established Cantonment Missouri along the river near here, and in 1820 a permanent post was built on the bluffs and named Fort Atkinson. Its population of over 1000 included military personnel of the elite Rifle Regiment and Sixth Infantry, some of their families, and other civilians. The Sixth U.S. Infantry occupied Fort Atkinson when it was abandoned in 1827. The fortification was a rectangular arrangement of one-story barracks made of horizontal logs, facing inward on an enclosed parade ground with loopholes on the exterior walls. Four entrances stood near the center of the four walls, cannons were mounted in bastions at the northwest and southeast corners, and a massively built powder magazine stood at the center of the enclosed area. Outside the fortification were a large council house for negotiating with the Indians, a gristmill, schoolhouse, sawmill, and other buildings, and a brick kiln produced thousands of bricks. Fort Atkinson represents an important early step in opening the West.