The Romantics, Transcendentalists and Bohemians
Booker T. Washington
G.W.F. Hegel (if and only if you can teach his philosophy right)
Dr. Martin Luther King Jr.
Anton LaVey (in my opinion, you have no buisness teaching people about christianity, without also teaching them about satanism)
The Intelligence Movement
I'm adding two more...
(No other Founding American Fathers, just those two, for their literary contributions and their philosophical contributions to Modern American Thought.)
I probably could name a few more, but these are my top choices.