by issuing an orange and black commemorative three-cent stamp in celebration of its 1956 bicentennial. Following the untimely deaths of its first five presidents, the college enjoyed a long period of stability during 1768-94 under Reverend John Witherspoon. Military occupation and the Battle of Princeton severely damaged the college during the war. In another disaster, fire destroyed Nassau Hall in March 1802. Student unrest led to an explosion at the Nassau Hall front door and several other incidents in 1814. Witherspoon was a prominent religious and political leader; and an original signer of the Declaration of independence and the Articles of Confederation. John Witherspoon was a prominent evangelical Presbyterian minister in Scotland before becoming the sixth president of Princeton in 1768. Upon his arrival, he transformed a college designed predominantly to train clergymen into a school that would equip the leaders of a revolutionary generation. Witherspoon made fundamental changes to the moral philosophy curriculum, strengthened the college's commitment to natural philosophy (science), and positioned Princeton in the larger transatlantic world of the republic of letters. Witherspoon's common sense approach to morality was more influenced by the Enlightenment ethics of Scottish philosophers Francis Hutcheson and Thomas Reid than the Christian virtue of Jonathan Edwards. Witherspoon thus believed morality was a science. It could be cultivated in his students or deduced through the development of the moral sense—an ethical compass instilled by God in all human beings and developed through education (Reid) or sociability (Hutcheson). Such an approach to morality owed more to the natural moral laws of the Enlightenment than traditional sources of Christian ethics. Thus, while "public religion" was an important source of social virtue, it was not the only source. Witherspoon, in accordance with the Scottish moral sense philosophy, taught that all human beings—religious or otherwise—could be virtuous. His students, who included James Madison, Aaron Burr, Philip Freneau, and John Breckinridge, all played prominent roles in the development of the new nation. Locally, Witherspoon was influential in leading the royal colony of New Jersey—a colony initially ambivalent about revolution—toward rebellion. In 1780 an amended charter declared that the trustees should no longer swear allegiance to the king of England, and in 1783 the Continental Congress met in Nassau Hall, thus making it the capitol of the United States for a short time. Nine Princeton alumni attended the Constitutional Convention of 1787, more than from any other American or British