The collection of the Duarte Historical Society and Friends of the Library focuses on the history of the City of Duarte and adjacent Bradbury. Its archive includes photographs, records, and other artifacts related to the settlers and families who developed Duarte, the local schools, and the local citrus industry..

Collections include pamphlets and ephemera documenting the growth, industries, transportation, and social organizations of Los Angeles and greater southern California; photograph collections; thousands of books related to southern California; and numerous archival collections related to indiviuals, the citrus industry, and businesses in the Inland Empire.