This collection consists of the personal, business, and family papers of Edmund Lyon (1855-1920), a noted Rochester inventor, humanitarian, philanthropist, and manufacturer. It includes family and business correspondence, diaries, notebooks, manuscripts of books and articles, financial records, photographs and memorabilia of Lyon, his wife Carolyn Hamilton (Talcott) Lyon, Harriet E. Hamilton (her aunt), and a few other members of the family.

The Ellwanger and Barry Papers includes the records of Ellwanger and Barry Nursery to 1918, including correspondence, order books, sketchbooks, stock record books, catalogs, price lists, inventories, and account books; records of Ellwanger and Barry Realty Company to 1963, including financial and legal papers, account books, payroll records, and blueprints for houses on the Ellwanger and Barry tract. Also business and personal correspondence, account books, and financial records of Patrick Barry, Charles P. and Julia Wald Barry, Bernard and Harriet Barry Liesching, and Arthur A. Barry, including much information about Rochester banks and civic organizations. Also family photographs and scrapbooks; memorabilia; diaries of Patrick Barry, 1857-72; and record of soldiers' bounties, 1862-1863.

The Ellwanger Family Papers includes the letters, diaries, scrapbooks, personal financial papers, etc. of George Ellwanger, his wife Cornelia (Brooks) Ellwanger, and his children and grandchildren. Box 3 contains correspondence to Helen and Margaret Ellwanger (daughters of Edward S. and Leah Cresswell Ellwanger) variously addressed to them individually and jointly. Their correspondents include: Gertrude Jekyll, Marianne Moore, Gertrude Herdle Moore, William Robinson, and Fletcher Steele. Letters from the following have been indexed: Patrick Barry, Algernon Sidney Crapsey, George Eastman, David Jayne Hill, Henry O'Rielly, Mrs. Caroline (Erickson) Perkins, and Charles Sprague Sargent.