Repauno Chemical Company, the first high explosives enterprise of the DuPont Company, was organized by Lammot du Pont (1831-1884). Lammot was William du Pont's cousin. The plant was constructed at Thompson's Point, New Jersey, near Gibbstown, at the confluence of Repaupo Creek with Delaware River. The plant began operations in May 1880, producing nitric and sulfuric acids, nitroglycerine, and "Atlas powder", a dynamite brand containing from 20% to 75% of nitroglycerine but still called "powder" because of unresolved patent issues with the California Giant Powder Company. Lammot du Pont and Repauno chemist W. N. Hill also worked to recover acids for reuse in dynamite production.

An application for a charter of incorporation of Repauno Chemical Company was filed with the Superior Court of Delaware by Lammot du Pont, Henry du Pont and Eugene du Pont on April 2, 1880, and the charter was granted on June 7, 1880 (Repauno Chemical Company Minute book, in: Acc. 500, Series II, Part 1, Vol. 1581). The company was reincorporated by a special Act of Incorporation which passed the Senate and House of Representatives of the State of Delaware on March 1, 1883. Lammot du Pont was the company's president and Henry du Pont was elected Secretary and Treasurer, but he transferred his duties to William du Pont. After Lammot's death in March 1884, William du Pont assumed the presidency, and J. Armory Haskell succeeded him in 1892. From 1895, the plant was consequently operated by Eastern Dynamite Company, E.I. du Pont de Nemours Powder Company, and E.I. du Pont de Nemours and Company Explosives Department.

The records of the Repauno Chemical Company document the period of William du Pont's association with the company as its treasurer and secretary, and later its president. Documents include extracts from board of directors' meeting minutes; high explosives patent specifications; some technical and operational materials; agreements between dynamite manufacturers on price adjustments and production and sales quotas by regions; financial statements of Repauno Chemical Company and other parties of agreements, excluding Hercules and Torpedo companies', whose statements are included with these companies' papers in corresponding subseries; and William du Pont's incoming correspondence, which primarily pertains to organization and finances. His outgoing correspondence of the same period is included with the Series II. General Correspondence. Subseries B: Outgoing Correspondence.

Repauno Company papers also include business correspondence and notes and memos of its first president Lammot du Pont, 1880-1884. This consists of incoming correspondence accompanied with occasional copies or drafts of Lammot du Pont's letters, supporting documents and enclosures. Topics include the preparation of agreements, litigation with California Giant Powder Company regarding dynamite patents, negotiations with railroad companies for explosives transportation, company operations, and experiments with dynamite ingredients, especially with sulphuric and nitric acids. (The main body of Lammot du Pont's correspondence is in Series A: General correspondence, Accession 384, Papers of Lammot du Pont, at Hagley).