This is a collection of letters, letterbooks, account books, scrapbooks, etc., concerning the families of Robert Hare and Thomas Willing. The letters and other documents include early family material, as well as documents written by numerous family relations, and some obviously only collected by them. The Willing family letters (1744-1901) are diverse, concerning family matters, business, society, comments on the Civil War, etc. There are numerous letters from Thomas Willing, many concerning his banking career, as President of the Bank of North America and later at the first Bank of the U.S. The Hare family letters (1724-1965) are more extensive and diverse, including much on travel in the U.S. and elsewhere. There is a letter from Robert Hare Jr. concerning steam engines, and letters from Horace Binney Hare concerning his education at Harvard, 1860, his trip to San Francisco and the west, 1862, and numerous letters written while a soldier in the Civil War. There are many letters from Horace Binney (1780-1875, DAB) to his daughter Esther, who was married to John Innes Clark Hare (1816-1905, DAB), concerning family travel and court cases. There are also letters from outside the family, such as those from Dorothea L. Dix. The bound volumes include, among others: Robert Hare letterbooks (1824-1825, 1841-1857), estate records, and laboratory expense accounts (1818-1860); G. H. Hare's journal or log of cruises aboard the U.S. United States (1841) and U.S. Flint (1845); Horace Binney Hare's 1862 journal of his trip to San Francisco. There are account books and accounts (1754-1795) kept by Thomas Willing; accounts of the controversy over the estate of John Innes Clark; and records of the First Colored Wesley Methodist Church of Philadelphia (receipt book, 1820-1848; minute book, 1827-1844). There are also Philadelphia court records, and minutes of the Common Council of the city, 1832.

The James V. Neel Papers document nearly every phase of the career of one of the founders of human population genetics in the United States. Neel was particularly thorough and organized, and retained virtually all of his significant scientific correspondence, committee reports, minutes of meetings, and drafts of manuscripts. The collection also includes data collected during Neel's work among the Xavante, Yanomanö and other indigenous populations. In a career that spanned the period from the late work of Thomas Hunt Morgan and Charles B. Davenport to the contemporary world of molecular genetics and nucleic acids, Neel knew, worked with, and corresponded with many of the most influential 20th century practitioners of genetics. The collection begins in earnest in 1943, after Neel had decided to focus on human genetics. Neel's work with Drosophila and none of his Drosophila manuscripts are found in the collection.