Transcontinental Railroad By 20gamer6 Dec 20, 1803 Louisiana Purchase wikkepediaThe united states required a huge section of the midwest from France. May 14, 1804 lewis and clark expedition archives.govLewis and Clark begin their expedition of the Louisiana purchase Jan 24, 1848 gold rush Apr 12, 1861 The begining of the Civil War history.comThe 620,000 thousand men died in the civil war