Eli Whitney (1765–1825) was an American inventor, best known for the invention of the cotton gin, enabling the mass production of cotton. Before his invention, separating the cottonseed from the raw cotton fibres, or lint, was a long and laborious process. But the success of the gin meant that the slavery system, which had until then been declining in the southern states of the USA, became revitalized as a result of cotton farming becoming profitable once more.

Cotton gin

Whitney designed his machine in 1793 and patented it the following year. The cotton gin (the word "gin" is a shortening of "engine") had a wooden drum embedded with hooks. These dragged the cotton fibres through a mesh while the seeds, which would not fit through the fine mesh, fell outside. Brushes continuously removed the loose cotton fibres to prevent jams. Smaller gins could be cranked by hand; larger ones were powered by horses and, later, steam engines.

Interchangeable parts

Whitney later designed and built muskets (long-barrelled guns) for the US Army. He favoured the idea of "interchangeable parts": identical parts that could be used in the production of the firearms. In this way, items could be assembled faster and repaired more easily. The idea caught on, paving the way for modern-style mass production.