If James Madison came back, he'd be peeved that he was the primary author of the Constitution and we honor his memory by not caring when his birthday is. When he stopped whining about that, and noticed that the system he designed has turned into a congealed ball of lard that eats money and excretes red tape, he'd probably be more humble about his contribution.
I'm fairly certain Ben Franklin wouldn't be impressed by our pace of innovation. He invented the post office and showed us electricity, and it still took us 200 years to come up with email. We're not good at connecting the dots.