I didn’t want this thread to disintegrate into a “when did it start“ conversation, but I did notice that the independent comic companies started up about that time. Then the older companies (Dc, Marvel) had to respond to the new threat so they seem to create a lot of interconnected stories like crossover‘s, Crises on earths, secret wars, etc. To me when the copper age started depends on which kind of company you’re talking about. Those who pushed new territory, or those who responded to the corporate threat.