Hamilton, Madison, and Jay used the pen name Publius for The Federalist Papers.
The Federalist Papers were a series of essays published in 1787 and 1788 to support ratification of the proposed United States Constitution. Alexander Hamilton wrote most of the essays, while James Madison and John Jay contributed important pieces.
Using a shared pseudonym allowed the essays to present a unified argument for the Constitution. Publius referred to Publius Valerius Publicola, an ancient Roman statesman associated with the establishment of the Roman Republic. The name therefore matched the essays' republican political themes.
The authorship of individual essays was initially concealed and later debated. Modern scholarship generally identifies Hamilton as the author of 51 essays, Madison as the author of 29, and Jay as the author of five, with several disputed assignments. The essays remain a major source for interpreting the Constitution's design.