I don't want to speak for him, but I think what garbagio is getting at is that the USA is a settler colony and nobody who lives here except indigenous people has a real attachment to the land that goes back further than 532 years, and the USA itself is not even half that age. Though I'm inclined to point out that the USA a very powerful civic religion, that people believe in very deeply and that this helps substitute for the lack of a real long history. You don't really need to be a "real" country like Russia with a 1000+ year history to be attached to your country and patriotic. Nationalism is cultivated through indoctrination into an established culture and civic tradition, not through having real indigenous roots in the land. After all, many places in the world have been conquered over and over and none of the original inhabitants remain.