John Adams graduated from Harvard College and James Madison from Princeton, so they could be called Ivy League grads. James Monroe attended the College of William and Mary but was a college dropout--because he left to fight in the American Revolution. William and Mary is not one of the Ivy League schools but has been called a "public ivy."
The chart shows John Adams and John Quincy Adams as having earned master's degrees, which is not so.
Nor does it show Nixon as having a J.D. I’m sure there are other errors.
W&M is a ‘public Ivy” because it’s nearly as old as Harvard, but is now a state school (and an exceptionally darn good one, at half the cost!)