This series contains three subseries: Genealogical notes and correspondence, Florence Sabin, and Mary Sabin. Genealogical notes and correspondence consists of material collected by Florence and Mary Sabin (1872-1953) and a publication about the history of the Sabin name.

The Florence Sabin subseries contains four sections. The first consists of clippings and articles (1900-85), obituaries and tributes (1953-54), miscellaneous biographical material (1903-60, n.d.), condolence letters to Mary Sabin (1953), and several undated speeches about Sabin. The second section contains material related to biographies by Mary Kay Phelan and Elinor Bluemel. Phelan published a biography of Sabin for young adults, Probing the Unknown, in 1959. There are two copies of the published book. Bluemel published Florence Sabin, Colorado Woman of the Century also in 1959. This section contains a published copy, reviews (1959), correspondence related to her research (1954-60), and miscellaneous notes (n.d.). Also included is an undated typescript by Bluemel entitled "The Genius of Florence Sabin".

The third section contains Sabin's financial records (1910-53), which include receipts, an account book, and investment records.

The fourth section consists of correspondence, printed material, memorabilia, and certificates related to awards and citations received by Sabin between 1910 and 1959. These are arranged alphabetically by the group or institution making the awards.

The final subseries is related to Florence Sabin's sister Mary and consists of miscellaneous clippings (1931-61); five small diaries and address books (1904-39); correspondence and printed material related to her involvement in the Hernando deSoto Celebration sponsored by the Mississippi Discovery Association (1937-41); her membership in Delta Gamma Kappa Society, a national honor society in education, (1937-40); and undated writings on Colorado history.

This series is organized into three subseries: Family, Friends and associates and Business. All of the subseries include both incoming and outgoing correspondence filed together chronologically and include items that were enclosed with correspondence, such as clippings and memorabilia.

The Family subseries contains letters to Florence and her sister Mary from various family members. However the bulk of the family letters consist of letters between Florence and Mary. There is approximately one linear foot of these letters dating from 1900 to 1951. They reflect the long and close bond between the sisters. Florence wrote regularly to her sister and these letters provide a detailed narrative of her life. Of particular interest are the early letters from Germany (1900-02) and those written during the thirteen years she worked at the Rockefeller Institute under the direction of Simon Flexner. Although they are mostly personal in nature, she also writes of her work.

The largest subseries contains correspondence with Friends and associates. The letters are both professional and personal letters and provide valuable insights into Sabin's life. They reveal a socially active woman of wide interests, who maintained close ties to colleagues and friends throughout her life. Long after Sabin left the Rockefeller Institute, she stayed in close contact with her former employees and the doctors there. Of note from her Rockefeller days is correspondence with physician Alfred Einstein Cohn (1938-51), Simon Flexner, pathologist and head of the Institute, and his wife (1924-43); Margaret Thuis Stein (1936-53), whose early letters to Sabin provide a detailed account of the activities at the Institute; Sabin's technician, Dorothea Fuller (1937-53); and Dr. Kenneth Smithburn and his wife, artist Florence Smithburn (1935-53). Dr. Smithburn spent 1938-40 in Central Africa and his letters to Sabin from his posting are of particular interest. In addition there are letters from Henry Allen Moe (1938-50), Secretary General of the Guggenheim Memorial Foundation; embryologist George Linius Streeter (1938-48); and Dr. Rodney Sidney Cunningham (1920-53). The Cunningham letters are particularly interesting because unlike other groups of letters, Sabin's replies are included. They were copied from originals at the Denison Memorial Library at the University of Colorado Medical School. Also of interest, because they date from Sabin's early years at Johns Hopkins, are a series of letters from Ella Strong Dennison (1915-32). Another side of Sabin's life is represented by letters from poets Axton D.B. Clark (1914-41) and Lola Ridge (1941), actress Katharine Hepburn (n.d.) and her mother Katherine Houghton Hepburn (1928-39), foundation executive Abraham Flexner (1943-46), lawyer and philanthropist Bernard Flexner (1940-46), archeologist Zelia Nuttall (1928-33), fellow Johns Hopkins University student Dorothy Reed Mendenhall (1952-53), and a long series of letters from playwright Edward Sheldon (1932-47). There is a series of letters from the Hooker family in this subseries. Although they are addressed to "Aunt Florence" it is not clear how or if they are related to Florence Sabin.

The final subseries consists of Business correspondence, 1925-53. This consists primarily of material related to her investments.

This series is divided in two subseries: Speeches and Writings.

The Speeches are divided into two sections, the first related to her work in public health in Colorado (1945-47) and the second on miscellaneous topics (1933-55).

The writings consist of her biography Franklin Paine Mall, The Story of Mind (1934), with related correspondence and reviews; a manuscript copy with notes of "Studies on the Cells of the blood and connective tissues with especial reference to their reactions in tuberculosis" (1925-38); reprints from Contributions to Embryology (1915-25); and miscellaneous reprints and writings (1897-1953).

This series contains correspondence, reports, printed material, minutes, and agenda related to Sabin's many professional and club activities. It is arranged alphabetically with two folders of miscellaneous organizations at the end. Following her retirement to Denver in 1938, Sabin became a major force in the crusade for public health reform in Colorado. The bulk of this material relates to public health issues and either directly or indirectly reflects her service on Governor John Vivian's Post War Planning Committee. Because she served on so many committees and consulted with so many organizations while serving in this capacity, much of this material is interrelated. The boundaries between the Colorado, Denver, and National Tuberculosis Associations are not always clear. There is unidentified statistical data throughout, which presumably was gathered by and for various organizations. Subjects covered include tuberculosis, hospitals and nursing services, stream pollution, dairy products, polio, health care for the indigent, and civil service.

This series contains printed material and correspondence related to a number of subjects, miscellaneous items, organizations, and people which were of interest to Sabin. Legislation and bills, which include those passed by the Colorado legislature as a result of Sabin's public health work, are of particular interest.

This series contains two subseries: Photographs and Memorabilia. The first subseries contains approximately 200 photographs. It is divided into five sections: Florence Rena Sabin, the Sabin Family, Mary Sabin, Friends and associates, and Miscellaneous. Because the photos are mostly undated, many may possibly date prior to 1872. The images of Sabin include early photographs of her as a child and young woman; Smith College; informal portraits and snapshots; formal portraits; photographs of her with her sister Mary; statues and a bust, paintings and drawings; and group photographs.

The Memorabilia subseries contains travel items (1929-41), poetry (1928-29), miscellaneous material (1893-1954), a publication on women at work in which Sabin was included (1939), her Rockefeller Institute retirement scrapbook (1938), a portfolio of famous American women's portraits, n.d., twenty-two date books (1938-52), seven address books (1915, n.d.), and three line-a day diaries (1902-42).