Duke has Raphael Thian's currency collection (stored in 5 albums). They also have an archive of Thian's papers.

The Currency Collection contains 4896 pieces, 1746-1982, of which all except a small number of coins and tokens are paper currency. Most of this money is domestic, but there are a limited number of foreign items, some of them quite old and interesting. Approximately two-thirds of the collection dates from the Civil War and one-fourth from the antebellum period.