A few of the most noted philosophers of the enlightenment era were:
John Locke; Argued that people have natural rights and that if a leader fails to protect those rights the people can remove that leader and choose another these ideas directly affected political revolutions.
Baron De Montesquieu: Argued that powers of a central government should be separated into three different branches.
Thomas Hobbes: Theory of the social contract calls for an all powerful government that retrains peoples worst impulses.
Jean Jacques Rousseau: Ideas on popular sovereignty and republicanism influenced later political movements
If you're referring to the Civil War era, in the years leading up to the war, once such compromise could have been that slavery could continue to exist where it was, but not spread to other states.
