Originally Posted by Shagnak
Steampunk mostly originated from work by SF/Fantasy authors Tim Powers and Blaylock (James?) in the 80s.

That's when the term was coined and books began to be overtly labeled as such, but the roots of Steampunk are widely considered to be much deeper, going back to actual Victorian era science fiction writers like Verne and Wells (it makes sense that their vision of the future would resemble their present, after all)