Lewis and Clark’s famous expedition lasted this long.
Two and a half years
One year
Three years
Four and a half years
Two and a half years. The 8,000-mile expedition officially began on May 21, 1804, from Camp Wood outside St. Louis and returned on September 23, 1806. Because of stops made beforehand in preparation for the journey, such as gathering supplies at Harpers Ferry, (West) Virginia, and Pittsburgh several different sites claim to be where the journey "really began" and give dates earlier than May 21.