- Four-page letter from Gerrit Smith of Peterboro [New York] to Lysander Spooner in Athol, Massachusetts, dated April 27, 1847, responding to Spooner's request for funds to support him during a visit to Boston as he writes his newest book. Includes list of names from whom Smith has collected funds, including S. E. Sewall, E. G. Loring, and H. B. Stanton.
- Three-page letter marked 'Confidential' to Lysander Spooner of Boston [Massachusetts] requesting his participation in an Executive Committee formed to advocate for the enlistment of blacks to fight in the Civil War. Signed by George L. Stearns on behalf of the Committee. This letter is part of the Slavery collection in New-York Historical Society.
- Three-page letter and envelope dated March 21, 1881, from Daniel McFarland in Texarkana, Arkansas [Texas], to Lysander Spooner in Boston, Massachusetts, notfying of his whereabouts and giving his new address. McFarland also writes that "in order to avoid the great notoriety which follows me wherever I go, I have taken the name of Daniel O'Brien for the present."