Lewis & Clark Adventure
http://www.lewisandclarktrail.com/section1/illinoiscities/Woodriver/history1.htm

http://www.nationalgeographic.com/lewisandclark/resources.html

http://www.nebraskastudies.org/0400/frameset.html

http://vintageprintable.com/wp-content/uploads/2010/08/Geopolitical-Map-US-Louisiana-Purchase1.jpg