What invention is Cyrus McCormick known for and when was it created?

Cyrus McCormick is best known for inventing the mechanical reaper, a significant innovation that was created in 1831, although it saw substantial improvements and commercialization thereafter. The mechanical reaper revolutionized agriculture by mechanizing the process of cutting down grain, which greatly increased efficiency compared to manual harvesting methods. This invention played a crucial role in the expansion of agriculture in the United States, particularly during the period of westward expansion, as fewer laborers were needed to harvest larger fields, allowing for increased production and a shift towards more commercial farming practices. McCormick's reaper is often cited as a catalyst for the agricultural revolution in the 19th century, enabling farmers to cultivate larger areas of land and contributing to the growth of the American economy.