It might undoubtedly have been considered that, as the want of a power in the Confederation to make uniform commercial regulations affecting the foreign and domestic relations of the States was one of the principal causes of the assembling of this Convention, such a power was implied in the terms of the resolution, which had declared the general principles on which the authority of the national legislature ought to be regulated. Still, it remained to be determined what kind of regulation of commerce was required by "the general interests of the Union," or how far the States were incompetent, by their separate legislation, to deal with the interests of commerce so as to promote "the harmony of the United States." In the same way, a power to obtain revenues might be implied on the same general principles. But whether the commercial power foreshadowed in these broad declarations was to be limited or unlimited; whether there were any special objects or interests to which it was not to extend; and whether the revenues of the government were to be derived from imposts laid at pleasure upon imports or exports, or both; whether they might be derived from excises on the manufactures or produce of the country; whether its power of direct taxation was to be exercised under further limitations than those already agreed upon for the apportionment of direct taxes among the States;—all these details were as yet entirely unsettled.

Two subjects, one of which might fall within a general commercial power, and the other within a general power to raise revenues, had already been incidentally alluded to, and both were likely to create great embarrassment. General Pinckney had twice given notice that South Carolina could not accede to the new Union proposed, if it possessed a power to tax exports.[211] It had also become apparent, in the discussions and arrangements respecting the apportionment of representatives, that the possible encouragement of the slave-trade, which might follow an admission of the blacks into the rule of representation, was one great obstacle, in the view of the Northern States, to such an admission; and at the same time, that it was very doubtful whether all the Southern States would surrender to the general government the power to prohibit that trade.[212] The compromise which had already taken place on the subject of representation had settled the principles on which that difficult matter was to be arranged. But the power to increase the slave populations by continued importation had not been agreed to be surrendered; and unless some satisfactory and reasonable adjustment could be made on this subject, there could be no probability that the Constitution would be finally ratified by the people of the Northern States.[213] It is necessary, therefore, to look carefully at these two subjects, namely, the taxation of exports and the prohibition of the slave-trade.

That a power to lay taxes or duties on exported products belongs to every government possessing a general authority to select the objects from which its revenues are to be derived, is a proposition which admits of little doubt. It is not to be doubted, either, that it is a power which may be attended with great benefit, not only for purposes of revenue, but for the encouragement of manufactures; and it is clear that it may often be used as a means of controlling the commercial policy of other countries, when applied to articles which they cannot produce, but which they must consume. A government that is destitute of this power is not armed with the most complete and effectual means for counteracting the regulations of foreign countries that bear heavily upon the industrial pursuits of its people, although it may have other and sufficient sources of revenue; and therefore, until an unrestricted commercial intercourse and a free exchange of commodities become the general policy of the world, to deny to any government a power over the exported products of its own country, is to place it at some disadvantage with all commercial nations that possess the power to enhance the price of commodities which they themselves produce.

But, on the other hand, the practice of taxing the products of a country, as they pass out of its limits to enter into the consumption of other nations, can be beneficially exercised only by a government that can select and arrange the objects of such taxation so as to do nearly equal justice to all its producing interests. If, for example, the article of wine were produced only by a single province of France, and all the other provinces produced no commodities sought for by other nations, an export duty upon wine would fall wholly upon the single province where it was produced, and would place its production at an unequal competition with the wines of other countries. But France produces a variety of wines, the growth of many different provinces; and therefore, in the adjustment of an export duty upon wines, the government of that country, after a due regard to the demand for each kind or class of this commodity, has chiefly to consider the effect of such a tax in the competition with the same commodity produced by other nations.

At the time of the formation of the Constitution of the United States, there was not a single production, common to all the States, of sufficient importance to become an article of general exportation. Indeed, there were no commodities produced for exportation by so many of the States, that a tax or duty imposed upon them on leaving the country would operate with anything like equality even in different sections of the Union. In fact, from the extreme northern to the extreme southern boundary of the Union, the exports were so various, both in kind and amount, that a tax imposed on an article the produce of the South could not be balanced by a tax imposed upon an article produced or manufactured at the North. How, for example, could the burden of an export duty on the tobacco of Virginia, or the rice or indigo of South Carolina, be equalized by a similar duty on the lumber or fish or flour of other States? Possibly, after long experience and the accumulation of the necessary statistics, an approach towards an equality of such burdens might have been made; but it could never have become more than an unsatisfactory approximation; and while the effect of such a tax at one end of the Union on the demand for the commodity subjected to it might be estimated,—because the opportunity for other nations to supply themselves elsewhere might be so precise as to be easily measured,—its effect at the other end of the Union, on another commodity, might be wholly uncertain, because the demand from abroad might be influenced by new sources of supply, or might from accidental causes continue to be nearly the same as before.

However theoretically correct it might have been, therefore, to confer on the general government the same authority to tax exports as to impose duties on imported commodities,—and the argument for it drawn from the necessities for revenue and protection of manufactures was exceedingly strong,—the actual situation of the country made it quite impracticable to obtain the consent of some of the States to a full and complete revenue power. Several of the most important persons in the Convention were strongly in favor of it. Washington, Madison, Wilson, Gouverneur Morris, and Dickinson are known to have held the opinion, that the government would be incomplete, without a power to tax exports as well as imports. But the decided stand taken by South Carolina, whose exports for a single year were said by General Pinckney to have amounted to £600,000, the fruit of the labor of her slaves, probably led the committee of detail to insert in their report of a draft of the Constitution a distinct prohibition against laying any tax or duty on articles exported from any State.

A similar question, in relation to the extent of the commercial power, was destined to arise out of the relations of the different States to the slave-trade. If the power to regulate commerce, that might be conferred upon the general government, was to be universal and unlimited, it must include the right to prohibit the importation of slaves. If the right to sanction or tolerate the importation of slaves, which, like all other political rights, belonged to the people of the several States as sovereign communities, was to be retained by them as an exception from the commercial power which they might confer upon the national legislature, that exception must be clearly and definitely established. For several reasons, the question was necessarily to be met, as soon as the character and extent of the commercial power should come into discussion. While the trade had been prohibited by all the other States, including Virginia and Maryland, it had only been subjected to a duty by North Carolina, and was subjected to a similar discouragement by South Carolina and Georgia. The basis of representation in the national legislature, in which it had been agreed that the slaves should be included in a certain ratio, created a strong political motive with the Northern States to obtain for the general government a power to prevent further importations. It was fortunate that this motive existed; for the honor and reputation of the country were concerned to put an end to this traffic. No other nation, it was true, had at that time abolished it; but here were the assembled States of America, engaged in framing a Constitution of government, that ought, if the American character was to be consistent with the principles of the American Revolution, to go as far in the recognition of human rights as the circumstances of their actual situation would admit. What was practicable to be done, from considerations of humanity, and all that could be successfully done, was the measure of their duty as statesmen, admitted and acted upon by the framers of the Constitution, including many of those who represented slaveholding constituencies, as well as the representatives of States that had either abolished both the traffic in slaves and the institution itself, or were obviously destined to do it.

This just and necessary rule of action, however, which limited their efforts to what the actual circumstances of the country would permit, made a clear distinction between a prohibition of the future importation of slaves, and the manumission of those already in the country. The former could be accomplished, if the consent of the people of the States could be obtained, without trenching on their sovereign control over the condition of all persons within their respective limits. It involved only the surrender of a right to add to the numbers of their slaves by continued importations. But the power to determine whether the slaves then within their limits should remain in that condition, could not be surrendered by the people of the States, without overturning every principle on which the system of the new government had been rested, and which had thus far been justly regarded as essential to its establishment and to its future successful operation.

It is not, therefore, to be inferred, because a large majority of the Convention sought for a power to prohibit the increase of slaves by further importation, that they intended by means of it to extinguish the institution of slavery within the States. So far as they acted from a political motive, they designed to take away the power of a State to increase its congressional representation by bringing slaves from Africa; and so far as they acted from motives of general justice and humanity, they designed to terminate a traffic which never has been and never can be carried on without infinite cruelty and national dishonor. That the individuals of an inferior race already placed in the condition of servitude to a superior one may, by the force of necessity, be rightfully left in the care and dominion of those on whom they have been cast, is a proposition of morals entirely fit to be admitted by a Christian statesman. That new individuals may rightfully be placed in the same condition, not by the act of Providence through the natural increase of the species, but by the act of man in transferring them from distant lands, is quite another proposition. The distinction between the two, so far as a moral judgment is concerned with the acts of the framers of the Constitution upon the circumstances before them, defines the limits of duty which they intended to recognize.

No satisfactory means exist for determining to what extent a continuance of the importation of slaves was necessary, in an economical point of view, to the States of North Carolina, South Carolina, and Georgia. There is some reason to suppose that the natural increase of the slave population in Virginia at that period more than supplied her wants; and perhaps the less healthy regions of the more southern States may have still required foreign supplies in order to keep the lands already occupied under cultivation, or to make new lands productive.[214] All that is historically certain on this subject is, that the representatives of the three most southerly States acted upon the belief, that their constituents would not surrender the right to continue the importation of slaves, although they might, if left to themselves, discontinue the practice at some future time.