Before the combine harvester farmers would need to hire groups of people to harvest crops before they rotted. Since there were only so many people available, the ability to harvest limited the volume of crops that could be grown. The harvester fixed that, doing the work of many people at once. This enabled the large farms, and relatively cheap food, we see today.
The reaper harvests wheat. There is a short amount of time that wheat can be harvested before it rots. Before the mechanical reaper men would use scythes, cutting from sunup to sundown. They could only plant what could be harvested in a two-week window, before the crop rotted, limiting the amount of grain and the amount of food. Reapers dramatically increased efficiency, allowing a reaper with a small number of helpers to do the work of many times the number of people.
Patrick Bell invented but did not patent a horse-drawn auto-reaper in Scotland. Obed Hussey patented the reaper a year before McCormick. They competed and fought but Hussey folded, selling his patent rights to McCormick in 1858. Historians suggest that Hussey’s early reapers were flawed technology, but that McCormick had higher quality standards. Hussey died in an 1860 train accident but his descendants argue, convincingly given the patent dates, that he is the true innovator of the modern reaper. Hiram Moore improved and patented a large-scale reaper, pulled by 20 horses.
Cyrus McCormick built an enormous harvester business that, later combined with others, eventually became International Harvester. Moore and McCormick did not like one another (Moore sued McCormick) and there are reports insinuating McCormick was somehow stealing Moore’s patents before they could be processed.
A hyper-litigious McCormick sued a railroad over an $8.75 overcharge then litigated the case for 20 years, including three visits to the US Supreme Court. He fired his little brother, the then foreman of his factory when McCormick was 62 years old.
Historians argue McCormick’s brother, Leander, preferred one-off production but McCormick wanted a factory that could mass produce using standardized parts. As McCormick’s company grew he consolidated competition via acquiring companies, patents, and (according to some historians) some amount of espionage.
Besides McCormick’s harvester, he also pioneered a new idea, easy credit for farmers to purchase the harvesters on affordable terms. Despite easy credit he lent money at 6%, the same rate he paid as a large and well-established manufacturer; he purposefully used self-financing to build sales volume, not as a profit center itself.