America has been fortunate in having a large number of smart, intelligent Presidents in its history.
This author would judge the twelve smartest Presidents, chronologically, to be as follows:
John Quincy Adams
James A. Garfield
John F. Kennedy
Who would be the smartest of all? Probably a tie between Jefferson and John Quincy Adams!
And who are the 12 dumbest Presidents in chronological order?
William Henry Harrison
Ulysses S. Grant
Warren G. Harding
George W. Bush
And who is the dumbest President in American history? Probably a three way tie among Harding, George W. Bush, and Trump!