Papers of the American railroad magnate and capitalist, whose financial interests included steamship, manufacturing, construction, and land companies. Philanthropist, trustee of the Hampton Normal and Agricultural Institute and supporter of Tuskegee Institute. Collection includes incoming correspondence (1856-1904); letterpress copybooks (1868-1901); legal and financial (including real estate) records (1797-1901); amd personal papers (1862-1901). Notable among the real estate records are documents relating to the furnishing and household expenses of Huntington's San Francisco residence, and records relating to the design, construction, decoration, furnishing, and maintenance of Huntington's palatial home on 57th St. in New York City.

Papers of the Connecticut fur trader. Collection includes correspondence (1817-1863), incoming, with some outgoing, encompasses over 1000 letters about the regional, national, and international fur trade; financial records (1777-1861), including account books, bills and receipts, and ledger sheets; and legal documents (1827-1861).

Account book, one volume, of what appears to be a lumber and hardware business, probably located in East Corinth, Vermont. There are also a few loose papers and one letter.

Account books and papers relating to the Phelps and Gorham Purchase in the Genesee Valley area of New York and Pennsylvania.

Miscellaneous material pertaining to commercial activity in Salem, Massachusetts in the late 18th and early 19th century.

Papers of a Kingston, New York family include correspondence (1740-1930); account books (1768-1770); a daybook (1758-1779); ledgers (1776, 1791-1808); journals, diaries, family Bibles, legal papers (1753-1804), and memorabilia. The bulk of the collection consists of business records of Cornelius Wynkoop and his sons, Cornelius C. Wynkoop and John C. Wynkoop.