Assuming they were not struck dead by future shock (photo, radio, television, telephone, mobile handsets), they would lose their damn minds that Black people have escaped slavery, non-landholders can usually vote, and the Presidency is (mostly) determined by the popular vote.

I do not think any of the founders, however amorphously the term is applied, would have interesting thoughts about cryptosystems for the examination of private photographs stored in commercial cloud setups.