History of Cosplay

"For almost 50 years, costume fandom has had a consistent and widespread following with costumers markedly influencing science fiction writers, artists and the media. Costuming, as an innovative, three-dimensional art form, has probed and broken all limits of imagination in SF and fantasy. From the first Worldcon in 1939 to last year's Worldcon in Philadelphia, costume fandom has emerged as a robust and dynamic force within science-fiction fandom. At the First World Science Fiction Convention in New York in 1939, a 22-year-old Forrest J Ackerman and his friend Myrtle R. Jones appeared in the first SF costumes among the 185 attendees. The future editor of Famous Monsters of Filmland was dressed as a rugged looking star pilot, and his female companion was adorned in a gown recreated from the classic 1933 film Things to Come. Both of them created quite a stir among the somber gathering of writers, artists and fen (plural of fan), and injected a fanciful, imaginary quality into the convention's overly serious nature. Frederik Pohl, in his book The Way The Future Was, described the couple as "stylishly dressed in the fashions of the 25th century" but feared that they had started an ominous precedent. He was right! So successful were their costumes that the following year, about a dozen fans turned out in their own "scientifiction" apparel. Now, over a half century later, costume fandom has come to represent a large segment of the hardcore genre audience. Artists like Kelly Freas, Wendy Pini and Tim Hildebrandt, authors like Julian May and L. Sprague de Camp, and fans by the hundreds dress regularly in costume. Groups, such as the U.K.‘s Knights of St. Fantomy, the Society for Creative Anachronism and the International Costumers' Guild, conduct business and ceremony in costume, and the masquerade has become the central event of most large conventions.

Source: Wikipedia