Aaron Burr did not help write the Federalist Papers.
The Federalist Papers constitute a series of 85 essays arguing in support of the United States Constitution. Alexander Hamilton, James Madison, and John Jay were the authors of these essays, and the three men wrote all together under the name of Publius.
Seventy-seven of the essays were published in The Independent Journal, The New York Packet, and The Daily Advertiser between October of 1787 and August 1788.