Lewis and Clark By ohutch Period: Feb 25, 1803 to Sep 25, 1806 Lewis & Clark Expedition Feb 28, 1803 Jefferson Obtained funds from Congress for Expedition Apr 30, 1803 Louisiana Purchased from France-Publically announced on July 4 Announced Publically on July 4 May 14, 1804 Lewis, Clark & Company depart St. Louis Nov 2, 1804 Pacific Ocean Sighted Mar 23, 1806 Expedition departs Ft. Clatsop Sep 23, 1806 Expedition arrives back at St. Louis