Autograph and typed letters signed (26) : New York, Washington, and Santa Barbara, to Edward Wagenknecht, [n.d.] and 1956-1962.

Appreciating Wagenknecht's memories of The Outlook [of which Theodore Roosevelt was editor]; explaining how to get permission to publish Roosevelt letters, and discussing various centennial projects planned in addition to Wagenknecht's book; praising Wagenknecht's Lincoln anthology; agreeing (in 1956) that "it's a `sad world' "; offering detailed suggestions after reading the manuscript of Wagenknecht's book on TR, and praising the finished product, The seven worlds of Theodore Roosevelt(1958); thanking him for his review of The Hyphenated Family (1960) and explaining his view of German responsibility for World War I; explaining why he almost voted for Kennedy in 1960; and discussing dramatic readings of his poems. Many written as Director of the Theodore Roosevelt Centennial Commission, at the Theodore Roosevelt House; and as Director of the Theodore Roosevelt Association. With a letter from Helen MacLachlan, 26 May 1958, to Edward Wagenknecht, saying that Mr. Hagedorn is feeling better after an operation; and a letter from Mary Hagedorn (Mr. Hagedorn's daughter and assistant), 1 August 1958, to Edward Wagenknecht, thanking him for some material related to the Lowell Institute.