At this point, you’d have to work to find somebody who isn’t at least vaguely familiar with the concept of cosplay. But it all goes back to the woman who first spent her free time painstakingly crafting her futuristic costume—for a convention back in 1939.
Over at Racked, Jennifer Culp has written about the legacy of Myrtle R. Douglas, who went by the Esperanto-derived nickname Morojo. As the 20th century sci-fi fan scene was coalescing, she was right in the middle:
Between the years of 1938 and 1958, she edited three separate long-running sci-fi fanzines (“editing” including all of the typing, mimeo, and physical work required to manufacture the zines, naturally) and wrote editorials for several major early sci-fi “pro”-mags in the early ‘40s.
But she made a particularly major contribution to fan culture in 1939:
For more than 10 years Morojo and Ackerman were an inseparable, intellectually compatible dream duo, and 1939 was an especially big year for the pair: they started their first major zine together, jointly financed the publication of teenage Ray Bradbury’s first sci-fi zine, and attended the first-ever World Science Fiction Convention (Worldcon) wearing “futuristicostumes” straight out of the 1936 H.G. Wells movie Things to Come — the FIRST FAN COSTUMES EVER WORN IN RECORDED HISTORY.
Those costumes were “envisioned, designed, and laboriously hand-made by Morojo,” according to Culp. For her own ensemble, Morojo transformed a satin ball gown into a romper and cape—very dashing. In successive years she wore a frog face mask made by Ray Harryhausen, and a “Snake Mother” getup that must have been something to see.
The practice took off almost immediately, with more and more Worldcon attendees donning costumes, and over the decades has expanded to become part of fan culture across the globe. Could always use a few more satin rompers with capes in the mix, though.