William S. Willis Jr. (1921-1983), anthropologist and ethnohistorian, contributed significantly to the understanding of the dynamics of inter-cultural exchange in a multicultural context. After receiving his doctorate from Columbia University, he was hired as the first African American professor of Anthropology at Southern Methodist University. Upon resigning in protest from SMU in 1972, he returned to teach at Columbia University until 1975. His final years were spent studying Boasian anthropology. The collection includes correspondence, lecture notes, manuscripts of Willis' writings, and working notes. Of note, are the memos concerning his leaving Southern Methodist University and his extensive research notes on Franz Boas' views on race relations in America.

One of the oldest houses in Philadelphia, Wyck is now a non-profit museum listed on the National Register of Historic Places. Nine generations of the Jansen-Wistar-Haines family owned the Wyck property from 1690 until 1973. The last family owner deeded 2.5 acres of land, the house and its contents, several outbuildings, a landscaped garden, and a small endowment to the Wyck Charitable Trust. The Wyck Charitable Trust and the Wyck Association now administer the preservation of the property and its educational services to the public. This collection contains diaries, letters, accounts, bills and receipts, deeds, and photographs. The collection as a whole is deepest for the period 1770-1970. Items of particular note include accounts of household expenses at Wyck from ca. 1790-1970; papers pertaining to the Academy of Natural Sciences of Philadelphia, Quaker schools, and social reform groups; agricultural and horticultural practices; and correspondence to and from cultural leaders of 18th and 19th century Philadelphia. The papers of the John S. Haines family (Ms. Coll. 52A) form part of the Wyck Papers. The papers cover the years 1845 to 1949 and are arranged into eight series.