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)