@ChristiJunior@neckbeard.xyz @moth @mrsaturday It was initially called the gay community until the word "lesbian" was coined to refer to homosexual women, and later "bisexual" to refer to those who were attracted to both sexes. The term LGBT wasn't widely accepted until the 90s.
Believe it or not, there use to be tension between the LGB and the transgender community, especially after the Stonewall riots back in 1969. Gays and bisexuals thought that transgender people were just "acting out stereotypes" and were illegitimate. Transgenderism being associated with homosexuality was also believed to amplify the idea that gay men must be feminine.