This collection contains materials related to the architectural work of Charles D. Maginnis and Timothy F. Walsh and their firm, Maginnis & Walsh, compiled by Robert P. Walsh, a draftsman and architect for the firm who later married Maginnis's daughter, Alice, and worked on a biography of Maginnis. It includes Maginnis's business correspondence, as well as materials authored by him on a variety of topics. It also includes drafts of a biography of Maginnis, likely by Robert P. Walsh. The collection contains architectural notes and drawings of Maginnis & Walsh projects, including at Boston College, St. Patrick's Cathedral in New York City, and elsewhere. A scrapbook compiled by Robert Walsh containing photographs, clippings, designs, and letterheads pertaining to the Maginnis and Walsh firm is also included.