Free Admission Wednesday at General Grant National Memorial - see INFO below. The NPS Manhattan Historic Sites Archive The National Park Service - Manhattan Historic Sites Archive is an online resource displaying over one thousand archival items. NPS The Manhattan Historic Sites Archive Learn more about General Grant National Memorial, and other National Park Service sites in Manhattan, at the Manhattan Historic Sites Archive! This archive is comprised of items related to the important individuals and events associated with six National Park Service historic sites in Manhattan (General Grant N. Mem., Hamilton Grange N. Mem., Theodore Roosevelt Birthplace N.H.S., Federal Hall N. Mem., Castle Clinton N.M., and Saint Paul's Church N.H.S.) and to the creation and preservation of these sites. The materials are diverse in type, ranging from photographs, to letters, to maps and prints. This three-year project to catalog, reorganize, and digitize the collections was funded by the National Parks of New York Harbor Conservancy through a grant from the Leon Levy Foundation. Materials were chosen for digitization based on a variety of factors, including both informational and visual content, fragility, and aesthetic qualities. More Info below.