Original meaning
Originalists of all stripes cite "The Federalist Papers". It is fairly tenuous to suggest that this represents a good source for the original "intent": after all, Alexander Hamilton, who wrote the majority of those essays, was absent for the greater part of the Philadelphia Convention, and John Jay did not attend it at all. However, James Madison, the principal framer of the Constitution also wrote a substantial amount of "The Federalist Papers". Also, to suggest Hamilton and Jay's absence from the convention implies their ignorance as to the Constitution's original meaning is demeaning to those two men and inaccurate. The collected anti-Federalist papers, of course, will be no use at all to a person searching for the original "intent" of the framers. However, as evidence of how a reasonable person at the time would have understood the words of the Constitution, "The Federalist Papers" and the anti-Federalist essays are evidence of direct relevance.
Federalist No. 2
Federalist No. 2 is an essay written by John Jay, the second of "The Federalist Papers", a series of 85 essays arguing for the ratification of the United States Constitution. These essays, written by Jay, Alexander Hamilton, and James Madison, were published under the pseudonym "Publius". Federalist No. 2, titled "Concerning Dangers From Foreign Force and Influence", was published on October 31, 1787, as the first of five essays written by Jay where he addresses the advantages of a unified government over separate sovereignties. He discusses how an undivided country enforces laws with more efficiency, resolves conflicts, and gives better protection from foreign influences (i.e. such as military force).