Figures like (a self-identified transvestite and gay liberation activist) and Sylvia Rivera (a founding member of the Gay Liberation Front and STARhouse co-founder) were at the vanguard. Rivera famously fought to include the "T" in the acronym when mainstream gay organizations wanted to drop trans people to appear more "respectable" to cisgender society.
While LGBTQ culture encompasses shared experiences of marginalization, the transgender community brings specific, transformative contributions to the larger whole.