In the winter of 1791–92, James Madison compiled a set of reading notes that scholars long assumed were meant to support the “party press” essays he soon published in the National Gazette, the new Republican newspaper edited by his college friend, the poet Philip Freneau. But as Colleen Sheehan has argued, Madison also conceived these “Notes on Government” for a more ambitious project: to draft a treatise on republican government that would apply the lessons of the American experience to problems that had long fascinated political theorists. The table of contents that opens the notebook indicates the outlines of the argument. The treatise, alas, remained unwritten – a reminder of the fact that Madison preferred to do his best political writing for himself, rather than the reading public. Alexander Hamilton, his co-author as Publius, felt fewer inhibitions and proved a more spirited polemicist. Had Madison gone back to Virginia in the fall of 1787, to aid in the ratification struggle in his native state, rather than returning to the Continental Congress, his twenty-nine contributions to The Federalist would never have appeared. Without Federalist 10 and 51 and a few other essays to guide our thinking, the modern concept of a “Madisonian constitution” might never have formed. Who knows: had Hamilton written nearly all of The Federalist, with a little assistance from John Jay, we might have been stuck with a “Hamiltonian constitution” all along.