The Phoenix Steel Company began in the late 18th century as a manufacturer of cut nails. It later became a major producer of railroad rails and iron and steel structural members. Claymont Division of the Phoenix Steel Corporation was established in 1960 when the company purchased the Claymont, Delaware steel plant from the Colorado Fuel and Iron Company. This small collection of materials originating from the Claymont steel plant includes miscellaneous plant announcements, catalogs, labor agreements, photographs, company-issued newsletters, and brief historical essays on the Phoenix Steel Corporation and its predecessors.

The Phoenix Steel Company began in the late eighteenth century as a manufacturer of cut nails. It later became a major producer of railroad rails and iron and steel structural members. Their records include minutes (1856-1929); stock ledgers; brief of title papers and property maps; legal and financial correspondence and tax papers; account books; and a works diary.