The Morningside Area Alliance is an organization working for community improvement on behalf of its member institutions in the Morningside Heights neighborhood in New York City. The organization was founded as Morningside Heights Inc. in 1947 through joint action of fourteen Morningside Institutions--Columbia University, St. Luke's Hospital, Cathedral Church of St. John the Divine, Teacher's College, Barnard College, Corpus Christi Church, Home for Old Men and Aged Couples, International House, Jewish Theological Seminary, Juilliard School of Music, St. Hilda's and St. Hugh's School, The Riverside Church, Union Theological Seminary, and the Women's Hospital of St. Luke's Center--with the expressed purpose of "[promoting] the improvement of Morningside Heights as an attractive, residential, educational, and cultural area." The collection includes much, if not all, of the material that was created by the organization as part of its daily business from 1947 to 1992, when the materials were accessioned into University Archives at Columbia University. This includes records of the Board of Directors and the various Committees within the Alliance; assorted publications, reports, pamphlets, and theses both acquired and created by the organization; files of the different offices within the organization; maps, plans, and photographs used and created by the Alliance for its work; and the collected materials and files created for the organization's projects in different subject areas--specifically buildings, community services and programs, public safety, schools, and the Morningside General Neighborhood Renewal Plan. The collection also includes a large quantity of material rearranged into subject files on different areas of concern within the organization.

The Pierrepont family papers (1761-1918) document the intersection of commercial, civic and personal interests across three generations of one of the most prominent and influential families of nineteenth century Brooklyn, New York. The bulk of the collection concerns the business dealings of Henry Evelyn Pierrepont from 1838 to his death in 1888. This especially includes an extensive set of accounting and transactional records concerning the Pierrepont Stores, the family's warehouse on Brooklyn's East River waterfront; these include records of ships arriving at the Stores and their cargoes delivered. Additionally, there are substantive correspondence, legal documents and other materials concerning the Union Ferry Company, of which Henry was an officer. In addition to commerce and shipping, a major theme of the collection is that of land acquisition in Brooklyn Heights and at the adjacent waterfront in the early nineteenth century, and the development of that property over the course of the century. Included in the collection are correspondence, deeds, indentures, leases, accounting records, diaries, maps, invoices, receipts, business proposals, legal filings, clippings, and historical and genealogical manuscripts.