Incoming and outgoing letters are predominantly between May Walden and her daughter Katharine Kerr Moore, dealing with personal and familial concerns. There is a scattering of letters addressed to Charles Hope Kerr and a number of letters to May Walden which relate to her Socialist Party activities. Although among the correspondents are several well-known people, most of them sent brief notes and/or signed form letters relating to the Socialist movement. Among these are notes from Theodore Dreiser, F. Scott Fitzgerald, Edward Everett Hale, Alan Lomax, Eleanor Roosevelt and Margaret Chase Smith. Letters of more interest to Charles Kerr include two from William Jennings Bryan (1897, 1901), one from James Russell Lowell (1884) and one from Frank W. Taussig (1900). There are also letters to May Walden from Clarence Darrow (undated), Helen Keller (1954), and Margaret Sanger (1921).