This vote, and the debate that preceded it, obviously had no overt or intentional bearing on the question of the spread of slavery into new states. But by implication it would have bearing on that question in the future. It is clear that the Framers intended that Congress should have the power to require any conditions it deemed proper for the admission of new states into the Union. It is to be lamented, then, that James Madison later wrote of this provision that it did not endow Congress with the power to name the prohibition slavery as a condition for admission as a new state:It is to be lamented, then, that James Madison wrote of this provision that it did not endow Congress with the power to name the prohibition slavery as a condition for admission as a new state:
“As to the power of admitting new States into the federal compact, the questions offering themselves are: whether Congress can attach conditions, or the new States concur in conditions, which, after admission, would abridge or enlarge the constitutional rights of legislation common to the other States; whether Congress can, by a compact with a new member, take power either to or from itself, or place the new member above or below the equal rank and rights possessed by the others; whether all such stipulations, expressed or implied, would not be nullities, and so pronounced when brought to a practical test. It falls within the scope of your inquiry to state the fact that there was a proposition in the convention to discriminate between the old and new States, by an article in the Constitution declaring that the aggregate number of representatives from the States thereafter to be admitted should never exceed that of the States originally adopting the Constitution. The proposition, happily, was rejected. The effect of such a discrimination is sufficiently evident.”
In Madison’s defense, it may be noted that he admitted in this letter that he was only able to avail himself “but very partially” of the “manuscript and printed sources of information on the subjects of your inquiry.” If he had consulted his records more closely, they should have led him to recollect that the Convention had given Congress very wide latitude in deciding the conditions of admitting new states. What is even more to be lamented, however, is that the Taney court used Madison’s letter as part of their reasoning when striking down the Missouri Compromise in the Dred Scott case.
Justice Daniel quoted Madison’s letter at length. And the argument by Justice Catron (a separate opinion in the Dred Scott case) follows Madison’s erroneous reasoning when he links the equality principle to the admission of new states: “And, secondly that the Act of 1820, known as the Missouri [60 U.S. 529] Compromise, violates the most leading feature of the Constitution – a feature on which the Union depends and which secures to the respective States and their citizens and entire EQUALITY of rights, privileges, and immunities.” For better or for worse, this vote taken at the Convention is an explicit rejection of the principle that new states must be admitted on conditions of equality.