James Madison was among those who had always believed that the 10th Amendment was unnecessary because its meaning was already implied by the structure of the Constitution. Nonetheless, he believed that amending the Constitution to add an explicit statement to that effect could do no harm; it might in some future instances do some good; and at any rate it would relieve the anxieties of those who were alarmed at the prospect of encroaching federal powers. When introducing what would later become the 10th Amendment in his initial proposal to the First Congress, he said:
Perhaps other words may define this more precisely than the whole of the instrument now does. I admit they may be deemed unnecessary; but there can be no harm in making such a declaration, if gentlemen will allow that the fact is as stated. I am sure I understand it so, and do therefore propose it.
His proposal might have successfully relieved the anxieties of all of the Antifederalists, if he had included all the words that they had asked for. But many opponents to the Constitution had wanted to do even more than make the Constitution’s implicit limitation of powers explicit. They had wanted to limit the powers of the federal government even further.
Every state ratifying convention that had recommended amendments to the new Constitution had requested that a declaration should be added similar to the one that was eventually adopted as the 10th Amendment. Half of those states, however, had asked that the clause look more like the one in the old Articles of Confederation: “every power, jurisdiction and right, which is not by this confederation expressly delegated to the United States” is reserved to the states. North Carolina had wanted to specify that the federal government could only exercise powers “particularly given” to it, and New York had wanted it to exercise only those powers “clearly delegated” to it. Virginia was the only state that had refrained from adding any qualifying adjectives to the delegated powers that were authorized by the Constitution. Madison later recounted that Virginia’s opponents to the Constitution had originally wanted to add the word “expressly,” but “after full and fair discussion, [it] was given up by them.” Madison’s own proposal for a bill of rights likewise omitted that word.