On John Locke: http://plato.stanford.edu/entries/locke/ — you can read the whole thing, or start at the section on the Two Treatises.
Thomas Hobbes’ moral and political theory: http://plato.stanford.edu/entries/hobbes-moral/ — I like the part about the state of nature is a state of war. He’s so cheery!
State constitutions of the Revolutionary Era: http://avalon.law.yale.edu/subject_menus/statech.asp
the Baron de Montesquieu: http://www.rjgeib.com/thoughts/montesquieu/montesquieu-bio.html