What language would we be talking? I am curious.
Tough to say, because of when this hypothetical cuts into history. Going way back, we'd have never taken this land from the native Americans and either have sought coexistence, or would have left when asked, because we wouldn't have imposed ourselves onto an otherwise peaceful group of people.
Regarding our personal lineage, we'd be either be speaking our ancestor's native language, or if our ancestors would have gone somewhere else, then we'd be speaking that language. Regarding the language of this land, I'm sure someone else would have taken this land from the Native Americans, in which case we'd be speaking their language.
We'd have never built enough infrastructure or technology to be where we're at, at any point in time, in which case any wars we've played a role in, would be greatly diminished, and I think it's pretty well accepted that the US played a very significant role in WWI/II, so those could have easily gone the other way.
What Rob wants is to have his cake and eat it too. He wants to enjoy the things that all of us slaves were forced to pay for, then he wants to say, "oh ok, now is the time to stop paying for stuff because I don't like it, but don't undo anything existing because I like it too much!!!", and of course he lacks the foresight to see how that would affect the future, but you only need to apply his ideologies to the past to see exactly how it would work out.