The Federalist Papers are 85 essays written by Alexander Hamilton, James MAdison and John Jay under the pseudonym "Publius." The documents were written in order to gain support for the ratification of the Constitution of the United States.
The Federalist Papers are significant because of the number of political issues they deal with. The essays discuss topics such as the separation of power, the tyranny of the majority, the problem of factions, the limits of democracy, the branches of government, the nature of a good republic, the importance of political institutions, etc.
Out of these papers, "Federalist No. 10" is usually regarded as the most important one. Other significant papers are No. 14, No. 84, No. 78, No. 70, No. 51 and No. 39.