Even cave people had capitalism. The males would go out and punch a lion with their fists, bring the meat home, pull a big rock slab shut behind them to close them off from the other people living in the cave, and maybe share with their wife or children if they were feeling generous.
“Economists have a singular method of procedure. There are only two kinds of institutions for them, artificial and natural. The institutions of feudalism are artificial institutions, those of the bourgeoisie are natural institutions. In this, they resemble the theologians, who likewise establish two kinds of religion. Every religion which is not theirs is an invention of men, while their own is an emanation from God.” - The Bearded One
I think it's hard to put a date on it because it spent a few centuries growing from feudal relations and feudal relations have some of the characteristics of capitalism.