What collection of essays defended ratification of the U.S. Constitution in 1787–1788?

The Federalist Papers are the collection of essays that defended ratification of the U.S. Constitution in 1787–1788.

Alexander Hamilton, James Madison, and John Jay wrote the essays under the shared pen name Publius. They first appeared in New York newspapers and explained how the proposed Constitution would structure government, control factions, protect the union, and divide power among branches.

The series contains 85 essays. Hamilton wrote the majority, Madison wrote several of the most frequently cited essays, and Jay contributed essays before illness limited his participation. The essays were aimed especially at New York’s ratification debate, although they circulated much more broadly.

The Federalist Papers were advocacy documents, not the official text of the Constitution. Their arguments later became influential sources for interpreting the Constitution, but they did not themselves have legal force. The Anti-Federalist writings were a separate body of criticism that warned against centralized power.