Correspondence is divided into two parts, Correspondence - General and Correspondence - Individual. The General section includes isolated letters, photos, slides, etc. from various people. An exception to this is his undated birthday cards (May 5th), Christmas cards and undated invitations. They are filed, unsorted, in separate folders, in the General file.

The Individual section contains more extensive correspondence from selected individuals. It is important to note also that there is a great deal of overlap between the correspondence files and the categories of organizations, publications, genealogy, and travel. If a letter concerned, for example, the Springer Opera House, it was usually filed with the Springer material. As a general rule, if the letter contains a date and address, the envelope is discarded. When not present on the letter, date and address information from the envelope is added to letters in pencil and bracketed. If the information on the envelope was not legible, or if the envelope has notes or other information written on it, it is retained and clipped to the letter.