Short answers, pulled from the story.
Forrest J Ackerman and Myrtle R. Douglas created the first costumes at the 1939 World Science Fiction Convention. They wore green capes and breeches that they designed and sewed themselves at the Caravan Hall of the New York City World Science Fiction Convention.
The term cosplay originated in the 1983 issue of a Japanese magazine. A writer from Studio Hard coined the word to describe fans dressing up as characters, and the term became common knowledge among fans within a year or two.
The first World Cosplay Summit took place at the Rose Court Hotel in Nagoya, Japan. Five cosplayers were invited from Germany, France and Italy to establish a global stage for the art form.
Cosplayers educate themselves in crafting specialties such as textiles, sculpture, face paint, fiberglass, fashion design, and woodworking. They often wear wigs, use contact lenses, and apply body paint to replicate specific characters.
Rochelle Keyhan, Erin Filson, and Anna Kegler started the Cosplay Is Not Consent movement in 2013. The movement addressed issues of photography without permission, verbal abuse, touching, and groping at conventions.