Those didn't amount to anything, either.
It's the Anglosphere that made it work. Twice, actually, since I consider the North and South to be two separate sub-civilizations.
Throwing the native American tribalists a bone: whoever it was built those Indian mounds had more of a civilization in what is now the US than did the French or Dutch or anyone else except us English speaking folk. And they were here first. We should give it back... only they were long gone before we showed up.
And while we're at it, let's give Ireland back to the Fir Bolg, Iraq back to the Sumerians, and Palestine back to the Canaanites.
(The building of vast mounds of earth shaped like animals is a noteworthy technological achievement, but does not make a lot of sense from a practical point of view. But then again, we have skyscrapers, which are also kind of stupid when you stop to think the concept through.)
