Cited: * "United States Iron Ore Production." Index Mundi. N.p., n.d. Web. 27 Sept. 2010. <www.indexmundi.com/minerals/?country=us&product=iron ore&graph=production>. * Cross, Gary, and Rick Szostak. Technology and American Society (2nd Edition). 2 ed. Alexandria, VA: Prentice Hall, 2004. Print. * Zantium. "History of Technology :: Steam engines -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. N.p., n.d. Web. 28 Sept. 2010. <http://www.britannica.com/EBchecked/topic/1350805/history-of-technology/10449/Steam-engines?anchor=ref367967>. * Schuyler, Tami. Scientists, Mathematicians, and Inventors: An Encyclopedia of People Who Changed the World (Lives and Legacies Series). Phoenix: Oryx Press, 1998. Print. * Stover, John F.. American Railroads (The Chicago History of American Civilization). 2 Sub ed. Chicago: University Of Chicago Press, 1997. Print.
Cited: * "United States Iron Ore Production." Index Mundi. N.p., n.d. Web. 27 Sept. 2010. <www.indexmundi.com/minerals/?country=us&product=iron ore&graph=production>. * Cross, Gary, and Rick Szostak. Technology and American Society (2nd Edition). 2 ed. Alexandria, VA: Prentice Hall, 2004. Print. * Zantium. "History of Technology :: Steam engines -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. N.p., n.d. Web. 28 Sept. 2010. <http://www.britannica.com/EBchecked/topic/1350805/history-of-technology/10449/Steam-engines?anchor=ref367967>. * Schuyler, Tami. Scientists, Mathematicians, and Inventors: An Encyclopedia of People Who Changed the World (Lives and Legacies Series). Phoenix: Oryx Press, 1998. Print. * Stover, John F.. American Railroads (The Chicago History of American Civilization). 2 Sub ed. Chicago: University Of Chicago Press, 1997. Print.