Sidney Breese was a U.S. Senator, 1843-49, and a justice of the Illinois Supreme Court, 1857-78. Three of the incoming letters are from William Martin of Alton, Ill., about business matters. Among the outgoing correspondence is a June 14, 1869 letter to Myra Bradwell, who led the movement to open the legal profession to women in Illinois, in which Breese offers support in building the reputation and circulation of the Chicago Legal News. Other outgoing correspondence includes eight letters, Feb.-Dec., 1843, to Pierre Menard, Breese's business agent and creditor, concerning business affairs.
Typescripts of these letters were obtained from Harry E. Pratt of Springfield, Ill., owner of the Martin letters, Gov. Henry Horner, owner of the Bradwell letter, and from the originals in the Menard collection in the Illinois State Historical Library.