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 Adams
Thomas Jefferson
John Quincy Adams
Abraham Lincoln
James A. Garfield
Theodore Roosevelt
Woodrow Wilson
John F. Kennedy
Richard Nixon
Jimmy Carter
Bill Clinton
Barack Obama
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?
Andrew Jackson
William Henry Harrison
Zachary Taylor
Franklin Pierce
James Buchanan
Andrew Johnson
Ulysses S. Grant
Benjamin Harrison
Warren G. Harding
Calvin Coolidge
George W. Bush
Donald Trump
And who is the dumbest President in American history? Probably a three way tie among Harding, George W. Bush, and Trump!