The John H. Gundlach Papers consist primarily of correspondence, clippings, notes, memoranda, and printed material that document Gundlach’s activities in city planning and civic affairs, as well as his interest in the theater and collecting manuscripts. The Civic Affairs Series comprises correspondence, memoranda, notes, and clippings arranged by the various St. Louis city improvement projects that Gundlach was instrumental in organizing. The Missouri Centennial Celebration Series comprises correspondence, notes, printed material, and clippings related to the organization and completion of the 1921 Missouri centennial celebration in St. Louis. The Theater Series consists of correspondence, clippings, and printed material. It contains material relating to Gundlach’s interest and support of St. Louis theater companies, including the St. Louis Municipal Opera. The Manuscript Collection Series consists of original manuscripts, a journal, transcripts of manuscripts that were contained in Gundlach’s personal collection, correspondence, and printed material. The series also contains information related to the donation of the John H. Gundlach Papers to the Missouri Historical Society. The Business Series consists of correspondence, printed material, notary commissions, and other records. The series comprises incomplete records of Gundlach’s realty business in St. Louis. The Biographical Series consists of clippings, eulogies, and invitations. The series contains information on Gundlach’s life and career. The Miscellaneous Series consists primarily of membership cards, membership certificates, notes, and correspondence, mostly relating to Gundlach’s participation in various fraternal, recreational, and civic organizations.