Fifteen years later, in 1819, President
James Monroe dispatched a military expedition (the
Yellowstone Expedition, led by Colonel
Henry Atkinson) to establish a series of forts along the Missouri. These forts were to support the American
fur trade and counteract British influence on the northern plains. The 6th US Infantry and
1st Rifle Regiments made up the military portion of the expedition, which arrived at the Council Bluff site on September 19. Their establishment of Fort Atkinson made it the first major American fort west of the Missouri River. It was located near
Fort Lisa and
Cabanne's Trading Post, private
fur trading establishments operated by major traders who were based in
St. Louis, Missouri. The expedition stopped to build
Cantonment Missouri, a winter camp along the river bottom below the bluffs. Abandoning plans to establish more forts upstream, the soldiers settled in for winter. The winter of 1819–20 was very harsh; a shortfall of government contractors left the garrison without sufficient supplies. The soldiers suffered widespread
scurvy (due to poor nutrition and lack of
vitamin C), which claimed the lives of over 200 of the 1,120 men that first winter. Estimates of the civilian deaths is possibly as high as double the military dead; no records were kept of their losses. In the spring of 1820, the Missouri River flooded Cantonment Missouri. The soldiers built a permanent camp atop Council Bluff, and renamed it Fort Atkinson. The site was designated on US Federal Government maps as "Fort Calhoun" in honor of the Secretary of War,
John C. Calhoun, however the US Army named the actual encampment after its first commander. During the 1820s, soldiers took
meteorological observations as research for the government. The garrison was involved in combat only in 1823. Members of the
Arikara tribe attacked a trading party led by
William H. Ashley along the Missouri River in present-day
South Dakota. Soldiers from the fort retaliated by attacking the Arikara villages. Although no American soldiers died in the brief skirmish, seven soldiers drowned on the way upriver when their
keelboat struck a log. They were counted as the first United States' casualties in the
Indian Wars on the
Great Plains. In 1827, the Army abandoned the fort at Council Bluff and reassigned its personnel to other locations, primarily
Fort Leavenworth. ==Re-activation of Fort Atkinson==