You people, I've seen it twice now, and there is a fundamental question about the plot.
The movie never explains why finding the treasure exhonerated Great-grandpa Gates. So there was a treasure city after all, big woo! The old geezer's name was still on a list and still could have helped kill Lincoln. I know that's now how the movie says it actually happened, but the movie never explains how finding the treasure city makes everybody else conclude Gates didn't help kill Lincoln.
Thoughts?