The Bank of Delaware was a statewide financial services company that was organized on June 1, 1795. It received its original charter on February 9, 1796, becoming the first bank in and of the State of Delaware. In 1865 it received a national charter under the National Banking Act and was renamed the National Bank of Delaware at Wilmington. It operated under this name until its 1930 failure and subsequent acquisition by the Security Trust Company. The name "Bank of Delaware" was revived by the successor company in 1958. The Bank of Delaware's holding company was merged into PNC Financial Corp. in 1989. The Bank of Delaware collection consists of minute books, stock certificate books, letter books, journals, and ledgers of the Bank of Delaware and nine of its predecessor, merged, and acquired financial institutions.

Walter E. Trabbold (1921- ) was vice president of the Bank of Delaware from 1968 to 1981, and spent forty-one years in the banking industry. He was a pioneer in bank automation, bank information systems, and cash management systems. The papers include Trabbold's personal collection of technical bulletins, annual reports, correspondence, several of his publications on the banking industry, as well as newspaper clippings and other material related to data and information management systems related to banking.