We left Charles Sumner proclaiming himself an independent man, not bound by any party and free to act in the United States Senate as his conscience dictated. His conscience and his political circumstances happened to agree on his making an antislavery speech when he got the chance on August 26, 1852. A slave to his own principles, he had no other choice than to declaim on the theme of freedom national, slavery sectional. After some further throat-clearing about how Sumner had to make the speech and he did not accept the dogma of the day that the Compromise of 1850 forever settled all slavery questions, he dug into the subject in detail:
The relations of the Government of the United States -I speak of the National Government- to Slavery, though plain and obvious, are constantly misunderstood. A popular belief at this moment makes Slavery a national institution, and, of course, renders its support a national duty. The extravagance of this error can hardly be surpassed. An institution, which our fathers most carefully omitted to name in the Constitution, which, according to the debates of the Convention, they refused to cover with any “sanction,” and which, at the original organization of the Government, was merely sectional, existing nowhere on the national territory, is now above all other things blazoned as national.
Sumner rightly noted, and would go on to document exhaustively, that the framers declined to name slavery in the Constitution. Instead they resorted to circumlocutions about people held in service and otherwise carefully ensured that they referred to slaves as persons, not property. This allowed them to argue, and Sumner to carry on decades later, with the notion that the United States did not affirm a right to property in man. Not everybody at Philadelphia had such scruples, of course. The slavery language usually originated in a more direct way and the convention revised it to something more oblique thereafter.
On the point of slavery not existing on the national territory, Sumner almost had it right. The national territory at the time of ratification included only the Old Northwest, from whence I write this. The famous ordinance organizing it did ban slavery, but neglected to do anything about the slaves already present in the territory. Their owners petitioned the Confederation Congress for a guarantee of their property, or at least a clear explanation of its status, and got silence. As a practical matter, that permitted slavery to continue. Well into the nineteenth century, freedom suits in the area could hinge on whether someone was brought into the territory and its successors before or after the ordinance took effect. It ended up functioning as no more than a marginal ban on introducing additional slaves.
Sumner may not have known that; the Northwest Ordinance remains an understudied subject to this day. He and his generation of antislavery activists took from it the precedent of the nation’s first slavery ban. The law still has a plausible claim to that on paper, which sufficed for rhetorical purposes whether Sumner knew better or not. Thus he emphasized just how the national men of the time used “national” as a practical synonym for “slavery,” whatever their party, had misunderstood the nation’s history and constitution. For a group heavy with lawyers and other men of letters, that did make an extravagant error.