This time period in film is rarely discussed especially on here. But I do think there are good gems to be watched like Cabiria, Les Vampires, A Trip to the Moon, and of course the most famous Birth of a Nation. My favorite film of this time period is Intolerance.
Probably The Immigrant, which is a couple of weeks away from celebrating its 100th birthday. If we're talking feature length then it is probably Cabiria, though the two lead performances in Broken Blossoms bring it mighty close.