hm... just got an idea to do something like this today. You barely beat me to it. I probably would have gone with "the sage of Monticello" for Jefferson and "the Gipper" for Reagan, though.
The only hint I critique is Unconditional Surrender Grant. You could do "Unconditional Surrender _______" that way you don't give away the answer in the hint.
I thought that Theodore Roosevelt was old "rough and ready", and it's "The Donald" (what his first wife Ivana called him), not the Don (at least not yet)
Great quiz! Very informational. I only knew like 15 before, but now I know all of them
(I hope) .