Federalist No. 38
Federalist No. 38, authored by James Madison under the pen name Publius, is the thirty eighth of 85 essays. Titled "The Same Subject Continued, and the Incoherence of the Objections to the New Plan Exposed", Madison discusses notable improvements over the Articles of Confederation. Slavery is one particular item that he writes about, as an improvement. The new Constitution introduces a mechanism for which to bring the institution to a close, but under the Articles "it is permitted forever".
It was published on January 12, 1788.