I've never understood this argument. How long does a territory need to be occupied for before the natives of that area can call it "their country."

Every country has a starting point, the USA's is just more recent.

We can’t undo the past. And, actually, European and African settlement of the Americas is an event that argues in my favor. There would be a lot more Native Americans today if their ancestors had had the ability to maintain territorial integrity. We should not voluntarily resign our descendants to the same fate.