It should have two other chapters
There should be a chapter on the itialian cinema, which gave us the epic film, (even before Griffith), and the Russian cinema, which brought the art form to it's peak in the 1920's. Then it would be perfect. I wonder, if somebody came up with the money, would the producers go back and do these two other epsiodes a decade after the original came out?
There should probably also be something done on the origins of Asian cinema. "Hollywood", "Cinema Europe" and an Asian equivalent would be the perfect trilogy.