Cutright, Paul Russell. Lewis and Clark: Pioneering Naturalists. New ed. Nebraska: University of Nebraska Press, 2003. Print.
Dillon, Richard H. Meriwether Lewis. Lafayette, CA: Great West Books, 2003. Print.
Furwangler, Albert. Acts of Discovery: Visions of America in the Lewis and Clark Journals. Illinois: University of Illinois Press, 1999. Press.
Gass, Patrick. A Journal of the Voyages and Travels of a Corps of Discovery. 2nd ed. Philadelphia: Matthew Cary, 1810. Web. 26 Sep 2013.
Jackson, Donald Dean, ed. Letters of the Lewis and Clark Expedition, with Related Documents, 1783-1854. 2nd ed. Urbana, Illinois: University of Illinois Press, 1978. Print.
Jefferson, Thomas. Thomas Jefferson to Meriwether Lewis, June 20, 1803, Instructions. The Complete Thomas Jefferson Papers. Ed. And Trans. Gerard W. Gawalt. Manuscript Division, Library of Congress. Reuters America, Inc., and The Reuters Foundation. Web. 26 Sep 2013.
Lavender, David Sievert. The Way to the Western Sea: Lewis and Clark across the Continent. Lincoln: University of Nebraska Press, 2001. Print.
Ronda, James P. Lewis and Clark among the Indians. Nebraska: University of Nebraska Press, 2002. Print.
Saindon, Robert A., ed. Explorations into the World of Lewis and Clark. Volume 2. Great Falls, MT: Lewis and Clark Trail Heritage Foundation, Inc., 2003. Print.
Meriwether Lewis, and Ordway, John. The Journals of Captain Meriwether Lewis and Sergeant John Ordway. Ed. Milo M. Quaife. Madison: The Society, 1916. Web. 26 Sep 2013. < http://archive.org/stream/journalsofcaptai00lewirich#page/n9/mode/2up>
Meriwether, Lewis, and William, Clark. Original Journals of the Lewis and Clark Expedition, 1804-1804. Ed. Reuben Gold Thwaites Volume One, Part I. New York: Dodd, Mead, & Company, 1904. Web. 26 Sep 2013.
Meriwether, Lewis, and William, Clark. Original Journals of the Lewis and Clark Expedition, 1804-1804. Ed. Reuben Gold Thwaites. Volume One, Part II. New York: Dodd, Mead, & Company, 1904. Web. 26 Sep 2013.
Woodger, Elin, and Toropov, Brandon. Encyclopedia of the Lewis and Clark Expedition. New York: Facts on File, Inc., 2004. Print.
The explorations by Pike are not well-known because they are mysterious. The main intentions of the expeditions are unclear to this day. Pike was not also well educated and during his explorations he never made any new discoveries. This is what has made his explorations be less known. Wilkinson had also stated that there was a conspiracy to separate Louisiana Territory and since he was a double agent for Spain. Having not found the sources of the Red River and the Mississippi has also made his explorations less justifiable. His explorations seemed to be filled with ill luck.
Maynard, C.W. Zebulon Pike: Soldier-Explorer of the American Southwest. New York, NY: PowerKids Press, 2003.
Magoon, K., and M. Mayberry. The Zebulon Pike Expedition. Minneapolis, MN: ABDO Publishing Company, 2009.
Brinkley, Douglas. American Heritage: History of the United States. New York: Viking, 1998.
Davis, Kenneth. American History. New York: Harper Collins, 2003.
Gutman, Bill and Anne Wertheim. The Look-It-Up Book of the 50 States. New York: Random House, 2002.
Turner, Frederick. The Frontier in American History. New York: Dover Publications, 1996.