Volume 3 — THE DECLARATION OF INDEPENDENCE AND THE CONSTITUTION OF THE UNITED STATES OUR TWO TITLE-DEEDS.
Reading edition
Letter to the Mayor of Boston, for July 4, 1851.

From the beginning, Mr. Sumner never missed an opportunity, in speech or letter, of invoking the Declaration of Independence as a rule of action. The following letter is an example.
Boston, July 3, 1851.
Dear Sir,—I have been honored by an official invitation to unite in the celebration by our City Council of the approaching anniversary of American Independence.
Though it will not be in my power to partake of this celebration, I wish not to seem indifferent to the kind attentions of your Committee or to the hospitality of Boston.
I venture to inclose a sentiment, suggested particularly by the occasion, and in harmony, I trust, with the convictions of all sincere lovers of the Union.
I have the honor to be, dear Sir,
Your faithful servant,
Charles Sumner.
The Declaration of Independence, and the Constitution of the United States,—the two immortal title-deeds of American liberties. Defenders of the Constitution, let us not forget the principles of the Declaration, but, for the equal support of both, in the spirit of our fathers, without compromise, and with a firm reliance on the protection of Divine Providence, mutually pledge to each other our lives, our fortunes, and our sacred honor. Hon. John P. Bigelow, &c., &c.