So I have an aluminum 29er and I broke the frame. Buying a replacement frame isn't an option (the manf doesn't sell frames alone). I'm watching Craigslist for a replacement used of that bike, but as an alternative, maybe I want a different kind of bike altogether. That's what I'm asking about now.

I often see people recommend an 80s or 90s steel Trek (MultiTrack, 830, 850, something like that) but as far as I've seen those are all 26inch and maybe 27.5inch. I want to stay with 29er. What's the oldest steel 29er I can look for?

Or, asking another way, when did 29ers first show up, and were they steel or aluminum?

(I'm new to biking as of last year so I don't know much bike history.)