Advertisement from 1884 for the twine binder version of the McCormick reaper. "The People's Favorite! The World-Renowned McCormick Twine Binder! Victorious in over 100 Field Trials! New and Valuable Improvements for 1884!" Cyrus Hall McCormick, Sr. (1809-1884) was an American inventor and founder of the McCormick Harvesting Machine Company, which became part of International Harvester Company in 1902. Although McCormick is credited as the "inventor" of the mechanical reaper, he based his work on that of many others, including Scottish and American men, more than two decades of work by his father, and the aid of Jo Anderson, a slave held by his family. Cyrus McCormick filed patents for the invention, and his achievements were chiefly in the development of a company, marketing and sales force to market his products.