- Two letters from Lysander Spooner to George Bradburn. A two-page note dated June 21, 1845, notifying him that Amasa Walker will be visiting the store of Emerson, Harris & Potter if Bradburn would like to see him. Followed by a one-page letter dated October 17, 1845, notifying him that he must leave Boston to attend to his mother in Athol [Massachusetts]., New-York Historical Society
- Four-page letter dated September 8, 1845, from Geo. [George] Bradburn in Bangor [Maine] to Lysander Spooner of Boston, Massachusetts, describing several newspaper and circular reviews of Spooner's book [The Unconstitutionality of Slavery], mentioning opinions given by [William Lloyd] Garrison and Bob [Robert?] Phillips., New-York Historical Society
- Draft of two-page letter dated September 19, 1845, from L.S. [Lysander Spooner] of Boston [Massachusetts] to [George] Bradburn notifying him of the sale of the Boston Chronicle to Hiram Cummings, and encouraging him to "start a paper" in Boston with the backing of Richard Hildreth., New-York Historical Society
- Four-page letter dated October 27, 1845, from Lysander Spooner in Athol [Massachusetts] to George Bradburn in Boston, discussing Supreme Court decisions related to slavery, the death of Spooner's mother, and the public reception of his book [The Unconstitutionality of Slavery]., New-York Historical Society
- Four-page letter dated December 26, 1845, from Lysander Spooner in Athol [Massachusetts] to George Bradburn in Boston [Massachusetts], expressing desire to distribute his book [The Unconstitutionality of Slavery] to members of the United States Supreme Court and discussing other opinions on the state of the abolitionist movement., New-York Historical Society
- Six-page letter dated January 7, 1846, from G. [George] Bradburn in Boston [Massachusetts] to Lysander Spooner in Athol, Massachusetts, discussing [Samuel E.] Sewall's criticisms of Spooner's work and also mentioning the acceptance by [Charles?] Allen and "Williams" of Spooner's petition., New-York Historical Society
- Four-page letter dated August 25, 1847, from L. [Lysander] Spooner in Boston [Massachusetts] to George Bradburn in Cleveland, Ohio, instructing on where to send letters to Mrs. [Elizabeth] Sargeant, and to pick up a letter from her friend, Miss Julia Johnson. Also discusses abolitionist activities and arguments appearing in Spooner's new book., New-York Historical Society
- One-page letter dated July 18, 1848, from L. [Lysander] Spooner in Boston [Massachusetts] to [George] Bradburn, notifying that he is leaving Boston for Athol because he has "nothing to eat" and that "the Abolitionists must flounder in their ignorance until they are willing to give me bread in exchange for knowledge.", New-York Historical Society
- One-page letter dated December 28, 1850, from Stephen P. Andrews in New York City, to Lysander Spooner of Boston [Massachusetts], reporting on the distribution of books sent by Spooner to Freeman Hunt, [William Cullen] Bryant, [Horace] Greeley, and Park [Parke] Godwin. Includes mention of a "card" [possibly a petition] that Andrews suggests having signed in Boston and then sent to New York for additional singatures., New-York Historical Society