A Sachem and Civil War adjutant to Ulysses Grant, Ely Samuel Parker was an important figure in the Seneca Indian nation during the first half of the nineteenth century. Trained as an engineer, Parker was deeply involved in the Senecas' land disputes with the Ogden Land Company and he played an important role in interpreting Seneca culture for a white audience, most notably as a consultant for Lewis Henry Morgan. Collected by Arthur C. Parker, the Ely Samuel Parker Papers include correspondence, manuscripts, and printed materials relating primarily to Seneca affairs, history, language, and culture, as well as politics, education, engineering, and the Civil War. Among Parker's correspondents were Henry Clay, Millard Fillmore, Henry M. Flagler, Lewis Henry Morgan, Henry Rowe Schoolcraft, Daniel Webster, and Asher Wright. Several letters relate to Parker's service as engineer of public buildings in Galena, Illinois, and to his Masonic activities. Among the noteworthy items in the collection are several essays on Seneca history and culture, a fragment of Parker's diary, 1847, and a significant quantity of material on the Seneca language assembled by Asher Wright.

These papers include materials on the Onondaga, Tuscarora, Seneca, Cayuga, and Oneida Indians, collected during the years 1928-1930 under the auspices of the American Council of Learned Societies' Committee on Native American Languages. Included are field notes, grammars, dictionaries, studies of Handsome Lake religion, medical prescriptions, comparative linguistics, and correspondence with Franz Boas. Contains data on consultants, texts, translations, paradigms, grammatical studies, and lexical files.