Short answers, pulled from the story.
The word disco first appeared in the United States in the summer of 1964 to describe a short sleeveless dress called the discotheque dress. This marked the first known use of the term to describe a cultural phenomenon before it was applied to music.
French expatriate Olivier Coquelin opened the first true discotheque in the United States named Le Club on New Year's Eve 1960. The venue was located at 416 East 55th Street in Manhattan and served as a sanctuary for marginalized communities.
The true birth of disco occurred in the underground clubs of New York City and Philadelphia during the late 1960s. This emergence happened within marginalized communities of African-American, Italian-American, Latino, and queer populations.
Disco declined as a major trend in the United States following the Disco Demolition Night on the 12th of July 1979. The genre continued to sharply decline in popularity during the early 1980s.
The release of the film Saturday Night Fever in December 1977 catalyzed the transition of disco from an underground subculture to a global mainstream phenomenon. The soundtrack dominated by the Bee Gees became one of the best-selling albums of all time.
A disco revival has been underway since the early 2010s and reached great popularity in the early 2020s. Modern day artists continue the genre's popularity and bring it to a whole new younger generation.