 In 1804 , fifty years before the city of Omaha was founded , the Lewis and Clark Expedition first arrived via the Missouri River . The 1806 Fort Lisa and 1820 Cabanne 's Trading Post were important fur trading outposts located in proximity to the river , along with earlier Fontenelle 's Post in Bellevue . The Engineer Cantonment was built by Captain Stephen Watts Kearny 's Yellowstone Expedition in 1819 . The Expedition 's craft , the Western Engineer , was the first steamboat to successfully venture up the Missouri River to the Omaha @-@ Council Bluffs area . 
