The Federalist Papers are a collection of 85 essays written by Alexander Hamilton, James Madison, and John Jay in 1787 and 1788. They were written to explain and defend the proposed Constitution of the United States and to persuade the American people to ratify it.
From Wikipedia
The Federalist is a collection of 85 articles and essays written by Alexander Hamilton, James Madison, and John Jay under the collective pseudonym Publius to promote the ratification of the Constitution of the United States. The papers themselves came to be known collectively as the Federalist Papers beginning in the nineteenth century.