Commerce was to be established between the people of the different states. The commerce of a free people is many times more valuable than that of slaves. Freemen produce and consume vastly more than slaves. They have therefore more to buy and more to sell. Hence the free states have a direct pecuniary interest in the civil freedom of all the other states. Commerce between free and slave states is not reciprocal or equal. Who can measure the increase that would have been made to the industry and prosperity of the free states, if all the slaves in the country had been freemen, with all the wants and energies of freemen? And their masters had had all the thrift, industry, frugality and enterprise of men who depend upon their own labor, instead of the labor of slaves, for their prosperity? Great Britain thought it policy to carry on a seven years' war against us principally to secure to herself the control and benefits of the commerce of three millions of people and their posterity. But we now have nearly or quite the same number of slaves within our borders, and yet we think that commerce with them and their posterity is a matter with which we have no concern; that there is "_no propriety_" in that provision of the national constitution, which requires that the general government--which we have invested with the exclusive control of all commerce among the several states--should secure to these three millions the right of traffic with their fellow men, and to their fellow men the right of traffic with them, against the impertinent usurpations and tyranny of subordinate governments, that have no constitutional right to interfere in the matter.