Federalist
2 of the 7 encyclopedias on this shelf carry an entry for Federalist. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
the name of an early political party in the United States. After the acknowledgment of the independence of the 13 colonies by the mother country, the first task that confronted the successful revolutionists was the erection of a government and the formulation of a constitution. When the deliberative body on whom devolved this duty met, it was discovered that there were various sentiments entertained by its members, these differences of opinion aligning themselves on opposite sides of the great question of organic union. One faction favored the erection of a nation with more or less absence of independence of its constituent members, while the other urged a federation of sovereign states, each one of which should retain its autonomy, and not be amenable to the general government any further than it by actual cession gave that government authority. Those favoring a strong or national organic union were called Federalists, and numbered in their ranks such men as George Washington, Alexander Hamilton, and others, while those favoring the the sovereignty of the States were called Republicans, among them being Thomas Jefferson, James Madison, and others equally distinguished. The Republicans in this contest were victorious. Later in the history of the country the Federalists became known as Whigs, while the Republicans were called Democrats. FEDOR. See FEODOR.
Aiton's Encyclopedia (1910)
a series of political essays. Between the 27th of October, 1787, and the 2d of April, 1788, seventy-seven essays were published in the Independent Journal of New York City. These essays were written by Alexander Hamilton, James Madison, and John Jay, over the signature of "Publius," and were addressed "to the people of the State of New York," with the purpose of influencing the voters of New York to ratify the new Constitution of the United States . These essays, with nine others, were afterwards published in a volume now well known as the Federalist. Their influence at the time was considerable. They are now of importance as showing the political thought of Hamilton's day, and the views of contemporaries upon the Constitution. Fifty-one of the essays were written by Hamilton, twenty-nine by Madison, and five by Jay.