Letter to Charles Sumner (Boston, 1864). http://oll.libertyfund.org/titles/2233,
Spooner criticised Senator Sumner of Massachussetts for not being rigorous enough in his condemnation of the unconstitutionality of slavery. Like all politicians, according to Spooner, Sumner made too many compromises once he entered office.
The text is in the public domain.
This material is put online to further the educational goals of Liberty Fund, Inc. Unless otherwise stated in the Copyright Information section above, this material may be used freely for educational and academic purposes. It may not be used in any way for profit.
Some four or five weeks ago, as I was in conversation with Dr. S. G. Howe and James M. Stone, they both mentioned that, on their first reading my argument on “the Unconstitutionality of Slavery,” they had been convinced of its truth; and Dr. Howe added, “Sumner always said it was true, but somehow or other he could not think it was practical.”
A few days afterwards I saw Dr. Howe, and repeated to him what I had understood him to say of you, as above, and asked him whether I had understood him correctly. He said that I had; “that is, he had understood you to say, in effect, that you did not see how my argument could be met.” I gave him some of my reasons for wishing his explicit testimony on the point, and he added, “I think I cannot be mistaken about it.” He finally said, “I will put the question distinctly to him tomorrow.”
On the 23d ult. I met him again, and he said that he did put the question to you the next day, in this way: “Mr. Sumner, I have heretofore understood you to say that Mr. Spooner’s position was logical, and that you did not see how it could be answered;” and appealed to you to know whether he had understood you correctly. He said you acknowledged that he had, and that you added that “a judge, who was inclined to decide doubtful questions in favor of liberty, would be obliged to decide that question [of the constitutionality of slavery] in the same way.”
At this last conversation, Francis W. Bird was present, and corroborated Dr. Howe’s statement by saying that you had made a similar statement about my argument to him, at Washington, some few years ago. He added that he said to you, “Why, then, in Heaven’s name, do you not take that position?” And that you made no reply?
In the foregoing account I have given faithfully the substance of their testimony, and very nearly their precise words, as taken down immediately after the last conversation.
I cannot doubt that their statements are true, for I had testimony, nearly as direct and conclusive, to the same point, a dozen years ago, from two or three different sources.Edition: current; Page: 
Since December 1851, you have been under oath, as a Senator, to support the Constitution; and have made the subject of Slavery your principal topic of discussion; and have made, during all that time, the loudest professions of devotion to liberty. Yet during all the same period you have been continually conceding that the constitution recognized the Slaveholder’s right of property in his slaves; that those held in slavery had no rights under the constitution; and that the general government could not interfere for their liberation.
It now appears from the testimony of Dr. Howe and Mr. Bird, that all these concessions against liberty, have been made in violation of your own convictions of truth, and consequently in violation of your official oath; and that while for a dozen years, you have been making the most bombastic pretensions of zeal for freedom, you have really been, all that time, a deliberately perjured traitor to the constitution, to liberty, and to truth.
And this you have been, that you might be a Senator from Massachusetts, rather than remain in private life, and do your part towards educating the people into a knowledge of the true character of the constitution. And having once entered the Senate through the door of perjury, and treason to liberty, you have been obliged to adhere to that position, because, by advocating the truth, you would be convicting yourself of your previous falsehood.
A Senator, who, from such motives, with loud professions of liberty on his lips, falsifies, in behalf of slavery, the constitution of his country, which he has sworn to support, is as base a traitor as any professed soldier of liberty can be, who should, for money, deliver up a post which he had sworn to defend. This treason, it appears, you have been continually guilty of for twelve long years; and your ostentatious professions of zeal for liberty during that time, have, as I think, been made, in great part, with a view to hide the real treason you were committing.
My argument, in its leading features, was published in 1845. And several additions to, and confirmations of it, have been made at intervals since.
If that argument is true, slavery, from its first introduction into this country, to this time, has never had any legal or constitutional existence; but has been a mere abuse, tolerated by the strongest party, without any color of legality, except what was derived from false interpretations of the constitution, and from practices, statutes, and adjudications, that were in plain conflict with the fundamental constitutional law. And these views have been virtually confessed to be true by John C. Calhoun, James M. Mason, Jefferson Davis, and many other Southern men; while such professed advocates of liberty as Charles Sumner, Henry Wilson, William H. Seward, Salmon P. Chase, and the like, have been continually denying them.
Had all those men at the North, who believed these ideas to be true, promulgated them, as it was their plain and obvious duty to do, it is reasonable to suppose that we should long since have had freedom, without shedding one drop of blood; certainly without one tithe of the blood that has now been shed; for the slaveholders would never have dared, in the face of the world, to attempt to Edition: current; Page:  overthrow a government that gave freedom to all, for the sake of establishing in its place one that should make slaves of those who, by the existing constitution, were free. But so long as the North, and especially so long as the professed (though hypocritical) advocates of liberty, like those named, conceded the constitutional right of property in slaves, they gave the slaveholders the full benefit of the argument that they were insulted, disturbed, and endangered in the enjoyment of their acknowledged constitutional rights; and that it was therefore necessary to their honor, security, and happiness that they should have a separate government. And this argument, conceded to them by the North, has not only given them strength and union among themselves, but has given them friends, both in the North and among foreign nations; and has cost the nation hundreds of thousands of lives, and thousands of millions of treasure.
Upon yourself, and others like you, professed friends of freedom, who, instead of promulgating what you believed to be the truth, have, for selfish purposes, denied it, and thus conceded to the slaveholders the benefit of an argument to which they had no claim,—upon your heads, more even, if possible, than upon the slaveholders themselves, (who have acted only in accordance with their associations, interests, and avowed principles as slaveholders.) rests the blood of this horrible, unnecessary, and therefore guilty, war.
Your concessions, as to the pro-slavery character of the constitution, have been such as, if true, would prove the constitution unworthy of having one drop of blood shed in its support. They have been such as to withhold from the North all the benefit of the argument, that a war for the constitution was a war for liberty. You have thus, to the extent of your ability, placed the North wholly in the wrong, and the South wholly in the right. And the effect of these false positions in which the North and the South have respectively been placed, not only with your consent, but, in part, by your exertions, has been to fill the land with blood.
The South could, consistently with honor, and probably would, long before this time, and without a conflict, have surrendered their slavery to the demand of the constitution, (if that had been pressed upon them,) and to the moral sentiment of the world; while they could not with honor, or at least certainly would not, surrender anything to a confessedly unconstitutional demand, especially when coming from mere demagogues, who were so openly unprincipled as to profess the greatest moral abhorrence of slavery, and at the same time, for the sake of office, swear to support it, by swearing to support a constitution which they declared to be its bulwark.
You, and others like you have done more, according to your abilities, to prevent the peaceful abolition of slavery, than any other men in the nation; for while honest men were explaining the true character of the constitution, as an instrument giving freedom to all, you were continually denying it, and doing your utmost (and far more than any avowed pro slavery man could do) to defeat their efforts. And it now appears that all this was done by you in violation of your own convictions of truth.Edition: current; Page: 
In your pretended zeal for liberty, you have been urging on the nation to the most frightful destruction of human life; but your love of liberty has never yet induced you to declare publicly, but has permitted you constantly to deny, a truth that was sufficient for, and vital to, the speedy and peaceful accomplishment of freedom. You have, with deliberate purpose, and through a series of years, betrayed the very citadel of liberty, which you were under oath to defend. And there has been, in the country, no other treason at all comparable with this.
That such is the character that history will give you, I have very little doubt. And I wish you to understand that there is one who has long believed such to be your true character, and that he now has the proof of it. And unless you make some denial or explanation of the testimony of Dr. Howe and Mr. Bird, I shall feel at liberty to use it at my discretion.