A) the writing and adoption of the Constitution
The Federalists favored the Constitution and its ratification, whereas the Anti-Federalists opposed ratification because they thought it gave too much strength to the national government.
The most famous effort in support of the Constitution came in the form of "The Federalist Papers," which were essays written by James Madison, Alexander Hamilton, and John Jay. They were originally run in serial fashion in several newspapers, and then were published in a 2-volume set in 1788, under the title, The Federalist: A Collection of Essays, Written in Favour of the New Constitution, as Agreed upon by the Federal Convention, September 17, 1787.