Nevertheless, on the day that it was first proposed to incorporate the three-fifths clause into the apportionment rule for the lower house, the measure passed overwhelmingly (9-to-2). Gerry had vocalized the lone objection to the proposal. Immediately after this vote, Wilson and Hamilton proposed to apply the same rule (which included the three-fifths clause) to the representation in the second chamber of the legislature as well. This proposal also passed, though by a much narrower margin (6-to-5). It is clear from the votes that those who objected to the new rule were opposed to proportional representation of any kind in the second chamber; they were not dissenting because they objected to the three-fifths clause as such.
The delegates moved on to other matters, and the subject of the three-fifths clause did not come before the Convention again until almost a month later. When it did reemerge it immediately became embroiled in the more contentious question of whether the states should be represented proportionally or equally in the two houses. Furthermore, even if they could agree that Congress was meant to represent the states proportionally, should they count only population (setting aside the question of slave or free), or should they also include a reckoning of the “property” in each state.
One other important development arose in the Convention during this month: the delegates increasingly began to see their interests as divided along a single geographical line. Madison was the first to articulate the suggestion that the small-state/large-state distinction was mostly imaginary: “the states were divided into different interests, not by their difference of size, but by other circumstances; the most material of which resulted partly from climate, but principally from the effects of their having, or not having, slaves.” These circumstances resulted in markedly different economies in the two regions, and each economy was built upon a complex of distinct interests. Since “the great division of interests in the United States” lay between the Northern and Southern States, continued Madison, each region should be given sufficient political power to protect itself from the other.
Others spoke of the three-fifths clause as a way to protect slavery itself. Edmund Randolph “urged strenuously that express security ought to be provided for including slaves in the ratio of Representation. He lamented that such a species of property existed. But as it did exist the holders of it would require this security.” Pierce Butler of South Carolina was more blunt: “The security the Southern States want is, that their negroes may not be taken from them, which some gentlemen within or without doors have a very good mind to do.” Virginians such as Randolph and Madison personally agonized over the evils of slavery; South Carolinians such as Butler tended to be more callous about the institution; but the members from these two states were united in their wish to keep the federal authorities from threatening their own state’s interests, especially after it became clear that voting in the Senate would not be proportioned based upon population. Increasing the political leverage of Southern States in Congress was one way of providing a measure of security from federal encroachment. Carolina had difficulty convincing even many of their fellow Southerners that counting slaves fully was an equitable resolution; Georgia was the only other state to fully embrace this solution.
Perhaps because some of the Southerners were overreaching, a few members from the North began to express misgivings about any inclusion of the slaves in the apportionment of representation. Gouverneur Morris was especially virulent against any inclusion of slaves in the rule for representation, particularly since no other form of property was included. He said he was “reduced to the dilemma of doing injustice to the Southern States, or to human nature, and he must therefore do it to the former; for he could never agree to give such encouragement to the slave trade as would be given by allowing them a representation for their negroes.”
Rufus King was at first an early supporter of the three-fifths clause, acknowledging that any equitable ratio of representation would have to account for the “superior wealth” of the Southern States. After listening to some of Morris’ arguments, however, he began to waver in his support, though for a while he was still willing to vote for the three-fifths clause “for the sake of doing something.” As the debates wore on, however, he became increasingly disinclined to accept it. More than 30 years later, King (then a senator) would come to believe that the Northern States had perhaps conceded too much when they agreed to the three-fifths clause: “The concession was, at the time, believed to be a great one, and has proved to have been the greatest which was made to secure the adoption of the constitution.”
On July 12, Gouverneur Morris suggested adding to the clause relating to the rule of representation “a proviso, ‘that taxation shall be in proportion to representation.’” Three Southerners in quick succession admitted the justice of Morris’ attempt to tie representation to taxation, and the South Carolinians immediately tried again to count slaves as equal to freemen.
From all of these debates, it is clear that the bone of contention among the delegates was confined to the question of including slaves in the rule of representation. The corresponding inclusion of slaves into the rule of taxation was never contentious. Unlike with representation, no one perceived a theoretical problem with the inclusion of slaves into a rule that sought merely to estimate a state’s wealth. Also, all of the Southern States had already agreed to adopt the three-fifths ratio for taxation under the Articles of Confederation; New York and New Hampshire were the only holdouts keeping the states from adopting this amendment. The relative indifference to applying the rule to taxation was also because no one expected the federal government to raise much money through direct taxation. For most of the Framers, tying the two issues of representation and taxation together was meant only for the sake of appearances. The primary purpose of the three-fifths clause, then, was to find a rule for representation that both the North and the South could accept; the same ratio was later tied to taxation only to give the (false) appearance that its primary purpose was not related to representation.