They've been around since 1874, and were originally designed for bicycle-riding messengers
The jockstrap was invented by C.F Bennett to provide comfort for bicycle jockeys working the cobblestone streets of Boston. Originally named the Jockey Strap, the term jockstrap has reportedly been in use since 1888.
C.F Bennett's company, Bike Web Company, produced jockstraps until 2016
The man who invented the jockstrap, C.F Bennett, set up a company called Bike Web Company, later changed to Bike. Bike were a leading producer of jockstraps until last year, when Russell Athletic purchased the company and its trademarks.