1831 - Cyrus McCormick Operates His Mechanical Reaper 1834 - The Refrigerator: An American Entrepreneurial Story 1836 - Samuel Colt Patents Five Shot Revolver 1837 - John Deere Invents the First Self-scouring Steel Plow 1844 - Samuel F.B. Morse Demonstrates the Telegraph 1850 - Expressmen: Butterfield, Wells and Fargo