James Madison was the principal author of the Federalist Papers, a series of 85 articles written in 1787-1788 to promote the ratification of the U.S. Constitution. Collaborating with Alexander Hamilton and John Jay, Madison contributed significantly to the establishment of the foundational principles of American government. The Federalist Papers articulated the necessity of a strong federal government while addressing concerns about potential tyranny. They provided vital insights into the framers' intentions and remain essential reading for understanding the Constitution's principles, the structure of American government, and the philosophy behind democracy.