I learned about three inventions and one inventor. The inventions are the semaphore telegraph, the cotton gin, and the hydraulic press. The inventor’s name is Eli Whitney. First, I learned about the semaphore telegraph. The semaphore telegraph relayed messages and were coded into symbols. The idea was transformed into an electric telegraph. Second, I learned about the cotton gin. The cotton gin separates seeds from the cotton. Cotton prices dropped and it ensured the civil war. Third, I learned about Eli Whitney. He was born in 1765 in Massachusetts. Whitney invented many things such as the cotton gin. He popularized interchangeable parts in 1798. Last, I learned about  the hydraulic press. It’s used to crush things. The press helped turn soybeans into a major American food crop.