Lewis and Clark Expedition By 20mastei Apr 30, 1803 The Louisana Purchase is signed by Thomas Jefferson Aug 30, 1803 News of the Louisana Purchase is announced May 3, 1804 Sargent Floyd is the first U.S. soldier to die past the Mississppi. Also the first and only one to die on the expedition. May 14, 1804 Louis and Clark offically start the expedition in St. Louis. Jul 4, 1804 They celebrated the first independence day past the Mississippi River Nov 4, 1804 Sacagawea, a pregant woman and her husband join the expedition as interpeters. Dec 17, 1804 The tempature is recorded as -45 degrees F. That is colder than they every thought possible in the United States. Feb 11, 1805 Sacagawea's son is born. Jean Baptiste Charconneau Nov 7, 1805 They thought they had reached the Pacific Ocean It was really the mouth of the Columbia River Sep 23, 1806 The Expepedition gets back to St. Louis