The Brooks Family Papers contain materials relating to Harold Allen Brooks, Sr., Mildred McNeill-Brooks, and their son, Harold Allen Brooks, Jr. The materials consist of correspondence, writings, financial documents, photographs, and research files. The latter contains materials regarding Frank Lloyd Wright, other Prairie School architects, and Charles-Edouard Jeanneret. The research files on Jeanneret bring together documents and photographs collected from around the world and provide comprehensive documentation of Jeanneret's personal life, influences, and architectural career. There is a presentation drawing by Euston made after the architect's first visit to the site in the spring of 1939 and a writing by H. Allen Brooks as to why he became an architectural historian as it relates to the presentation drawing.