Ok, besides stating the present then (and I think even that would be problematic for a multitude of reasons), when could you say was a time where America was at its best and didn't coincide with suppression of racial minorities, women, the lgbt community, etc.?
I really don't think Moore is right in picking the time he chose, but I think you could make the same argument that many are making here about any point in history, with any country, and that makes it impossible to answer the question that was asked.