Where were the Federalists Papers published?

The Federalist Papers, numbered essays written by James Madison, Alexander Hamilton and John Jay under the shared pseudonym "Publius," were published in two New York newspapers: The Independent Journal and The New York Packet between October 1787 and August 1788. They were intended to encourage the States to ratify the new Constitution by explaining the benefit of uniting under a central government while still retaining a degree of sovereignty.

The essays were later collected into a book and published as The Federalist; they weren't called the Federalist Papers until sometime in the 20th century.