Henry du Pont's correspondence dates from his days as a student at Mt. Airy College and at West Point. Although there is a very small amount of information on the evolution of the Du Pont Company after the Civil War, the collection is more focused on local business, farming, and politics, and on Henry du Pont's militia career and the defense of Delaware during the Civil War.

Henry du Pont's miscellaneous papers include appointments, memberships, and commissions from his military career, both in the army and the state militia. From West Point, there is a notebook on military engineering, a roster of cadets, and a topographical map of West Point made by him. There is a list in his hand of Delaware men who served in the Civil War. There are also papers created by Henry du Pont in settling the estates of several family members, including Alexis I. du Pont and his maternal uncle, Joseph Charles Dalmas. There are also copies of Henry du Pont's own will and estate inventory. Also included are Henry du Pont's personal accounts and his accounts with E. I. du Pont de Nemours & Co., as well as other business papers, such as mortgages, deeds, leases, and lists of securities and real estate.