Short answers, pulled from the story.
Cosplay grew out of fan costuming at science fiction conventions. Forrest J Ackerman and Myrtle R. Douglas wore the first convention costumes at the 1st World Science Fiction Convention in New York City in 1939, dressed in outfits Douglas designed called "futuristicostumes."
The term was coined by someone at Studio Hard in an article published in a Japanese magazine in June 1983. The word was created deliberately to avoid the old-fashioned connotations of the existing Japanese translation of "masquerade."
The World Cosplay Summit is the most well-known international cosplay competition, selecting cosplayers from 40 countries to compete in the final round in Nagoya, Japan. It was first held on the 12th of October 2003 at the Rose Court Hotel in Nagoya, and the championship competition began in 2005.
The largest single event featuring cosplay is Comic Market, also known as Comiket, a semiannual doujinshi market held in Japan during summer and winter. Hundreds of thousands of manga and anime fans attend, with thousands of cosplayers gathering on the roof of the exhibition center.
"Cosplay Is Not Consent" is a movement against sexual harassment in cosplay communities, started in 2013 by Rochelle Keyhan, Erin Filson, and Anna Kegler. Starting in 2014, New York Comic Con placed large signs at its entrances with this message and reminded attendees to ask permission before photographing cosplayers.
Japanese manufacturers of cosplay costumes reported a profit of 35 billion yen in 2008. Japan is also home to the two most widely read cosplay magazines, Cosmode and ASCII Media Works' Dengeki Layers, with Cosmode holding the largest market share and publishing an English-language digital edition.