In 1893, Whitcomb Judson invented the sliding fastener, or zipper, to replace buttonhooks on shoes. The sliding fastener was not called a zipper until much later, though. In 1923, the Goodrich Company gave the name "Zipper" to boots that closed with a sliding fastener. People were much more charmed by the fastener than by the Zipper boots. Soon, everyone was calling the fastener itself a zipper. And the name stuck.
Walter Hunt never meant to invent the safety pin. But, so the story goes, he owed a man money. The man gave Hunt a piece of wire and offered him $400 for anything he could invent. Hunt twisted the wire into a safety pin. He patented it in 1849, and it is said to have made the man who bought it rich.