Though the Miscellaneous Manuscripts collection is composed of items that do not fall readily into any other existing collection, the two dominant intellectual areas represented in the collection are Early American History and History of Science.

The Anthony F. C. Wallace Papers include correspondence to and from 20th century anthropologists, ethnologists, historians, linguists, and psychiatrists and provides a wealth of resources for the study of technological and social change, American Indians, culture and personality, revitalization movements, the anthropological study of religion, and the cultural and biological bases of behavior. In addition to Wallace's correspondence, research notes, and drafts, the collection includes Wallace family correspondence and photographs, as well as Wallace's writings from childhood through recent years.

For many years referred to as the "Franz Boas Collection of American Indian Linguistics," this collection consists of a large body of linguistic and ethnographic material gathered together by Boas and many of his colleagues and students primarily from the 1890s to the 1940s. It contains the bulk of Boas's own fieldwork material, with the main exception of most of his Inuit and earliest Northwest Coast fieldwork. It contains the majority of the work sponsored by American Council of Learned Societies Committee on Native American Languages, which was directed by Franz Boas, Edward Sapir, Alfred Kroeber, and other academic linguists from 1927-1937. The collection, however, also contains related kinds of fieldwork and derived secondary materials created outside the auspices of this Committee, both earlier and later. The first deposit of the material arrivied in 1945. Subsequently, additional related materials were donated and added, as noted in the listings. Additionally, the documentary materials produced by some of the early projects (1945 to circa 1955) of the APS Phillips Fund for Native American Research were added to this collection. The collection has grown to over 80 linear feet of material representing at least 166 languages and dialects from the United States, Canada, and Mexico. The formats range from field notes and ethnographic texts to slip files, vocabularies, lexica, and grammars, and dozens of linguists and Native consultants are represented.