history of the Ret-con universe

I was watching "Smallville" the other day, and it got me wondering about the history of the ret-con universe. On the show, the JSA operated in secret until they were driven completely underground. I wonder, do we have any ideas weather or not there might have been meta-gene activations before the current crop? Maybe some historical/mythological characters were early metas. And maybe, just maybe some of them are still around.... something to think about, yes?