Thus it is plain that by the legitimate and intended operation of the Constitution, slavery had come to that stage of its existence, when it must either prepare for its own gradual decline and ultimate disappearance, or it must provide means for invigorating and prolonging its life. There was only one way in which its power could be increased and for some time yet firmly established, viz.: by the reopening of the infamous and almost universally condemned African slave trade. This would have accomplished a double purpose. It would have increased the numbers of the South, and enabled them measurably to balance the representation of the North, as well as to extend their dominion over the Territories, and lay the foundations of new States; or, in case of their success in destroying the Union, it would enable them to carry out their cherished schemes of empire, as an independent power. But, what was, perhaps, more important, it would tend to prolong, if not to perpetuate slavery, by infusing new supplies of barbarism among the African race, lowering their present grade of civilization, retarding their improvement on the whole, and thus postponing the inevitable day of their liberation.
There are strong indications, in the early proceedings of the conspirators, that they seriously entertained the design of replenishing their gangs of laborers from the shores of Africa. It was only after the contest had assumed a serious aspect, and the immense difficulties of their position began to dawn upon them, that they were compelled ostensibly to abandon that design. They were compelled to conciliate the border States, which were all opposed to the foreign slave trade. Virginia, whose chief annual income was derived from the sale of her slave population, rather than from the productions of their labor, was an indispensable ally to the rebellion, and she would hardly assent to the importation of Africans, in competition with her own supply. Moreover, it began to be obvious that the aid of foreign powers would be desirable; and their intervention, if to be obtained at all, could not be solicited or hoped for, without the most explicit disavowal of an intention to reëstablish a traffic which had already been denounced as infamous and piratical by the leading powers of the world. The rebels, therefore, were compelled by the exigencies of their condition to prohibit the slave trade in their permanent constitution. Doubtless they would never have done this, had they not been vigorously assailed by the Federal Government, and forced to modify their purposes with a view to conciliate support at home and abroad.