Reports and studies, including plans, blueprints, photographs, publications, contracts, and drawings pertaining to transportation, parkways, and city planning projects in Queens, Westchester County, Long Island, Buffalo, and New York, New York; Bethlehem, Pennsylvania; and other places. Also, includes planning material pertaining to the 1964 World's Fair in New York City and a report prepared for Cornell University on Cornell Heights, 1987.

Scrapbooks of printed brochures, plans, and photographs of McAvoy projects, and similar loose items.

Photographs, scrapbooks, family Bibles, and memorabilia primarily of the Horn family but also including the Freydiger and Hinte families of Germany. The collection includes an American Legion Auxiliary scrapbook from Queens County (1941-1942), a photo album of Cornell University in the 1940s, a family portrait and some of Marilyn Horn's publications.