Most of the correspondence reflects the building of the Museum's library collection and the ordering of books and periodicals from sellers around the world. The library's growth through gifts is also well represented through a steady correspondence with potential and actual donors. Some letters deal with research queries. The 1929-1930 correspondence comprising the Special Libraries Association, one of Vanderbilt's professional affiliations, is in a separate file since it consists of letters sent from other participating libraries as well. Earlier correspondence pertains to Vanderbilt's trip to Europe where he spent a year purchasing books. From London, Paris and Lausanne, he corresponded extensively with Kimball and his assistant Mary Radclyffe Furness reporting on his activities. There is also some correspondence generated by a few of the librarians who preceded Vanderbilt. The "Administrative issues" series, "Personnel" subseries contains directives Kimball sent to multiple staff or all, including library personnel.