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.
Anti-Federalist Papers
Following its victory against the British in the Revolutionary War, the United States was plagued by a variety of internal problems. The weak central government could not raise taxes to cover war debts and was largely unable to pass legislation. Many early American politicians and thinkers believed that these issues were the result of the Articles of Confederation - the first governing document of the United States. In 1787 a convention gathered in Philadelphia to attempt to amend it. Soon, however, the gathering shifted its focus to constructing a newer and more powerful Constitution for the fledgling country. Two main competing factions emerged, the Federalists and the anti-Federalists. The former supported a more powerful central government while the latter opposed it.