Just curious what baseball fans think is indeed the steroid era...

I think 'roids were used before we may have thought they were.  I think they became more common in the 90s, but were used in the 70s and 80s as well.  One guy I think of in the 70s and 80s is Brian Downing. That guy was jacked and didn't seem like much of a ballplayer but could hit with power.  I'm sure some of you can think of other players as well. 

I have no doubt that there was an odd player here or there who experimented with PED back in the 80s.   However, conventional wisdom at the time was lifting weights was bad for your game.   You'd see an occassional Greg Luzinski but they'd be more "thick" than "jacked".    I really do think it was Canseco who brought 'roids to the game.   Not because he was swoll up but because he was jacked and good.  So, naturally, other players said "What are you doing?"

Leyritz

I think that players have been using since the 1960s because Mickey Mantle received shots from Dr. Feel Good who was known for injecting steroids into JFK and other celebrities. 

I don't even think it was as much usage that changed the game as it was the quality of the drugs. I think PEDs really started to make huge advances in quality and efficiency going into the 90s, but I'm definitely not an expert. It would be worth researching.