The Inventor Of Cosplay
The inventor of Cosplay was Myrtle R. Douglas, aka Morojo. Myrtle was a Science Fiction fanzine editor. In 1939, she created costumes, based on an H.G. Wells movie, for her and her boyfriend to wear to the first World Science Fiction Convention. Of course, within several years, costumes became integral to Worldcon. (Cosplay also became huge worldwide, with events allowing people to dress up as characters going on at some point during an entire calendar year.)
Reddit User -Marmorset