Charles H. Mason (1886–1949) was employed for thirty-five years by Pierre S. "P.S." du Pont (1870-1954), the industrialist, entrepreneur, philanthropist, and horticulturalist who developed Longwood Gardens in Kennett Square, Pennsylvania. Mason worked as chief chauffeur and garage manager for du Pont. He lived with his family in a residence called "The Anvil" on the property at Longwood Gardens. This small collection includes Charles H. Mason and Marguerite Mason's journals (dictated by them and handwritten by Ann Mason, Charles Mason's sister) describing their early years in Lewes, Delaware.

Miscellaneous records including information about educational facilities in Delaware.

Longwood Gardens is a series of formal display gardens in Kennett Square, Pennsylvania, that was developed by Pierre S. du Pont (1870-1954) after he purchased the site from the Peirce family in 1906. The collection is comprised of two oral history interview projects. The first is with Eddie Dowling (1889-1976), an actor, screenwriter, playwright, director, producer, songwriter, and composer. The second project is commissioned oral histories with people with remembrances of du Pont and the development of Longwood Gardens.

Francis Gurney du Pont (1850-1904) was the youngest son of Alexis I. du Pont (1816-1857) and Joanna Smith du Pont (1815-1876), and grandson of Éleuthère Irénée "E.I." du Pont (1771-1834), founder of E.I. du Pont de Nemours & Company, a chemical company more commonly referred to as the DuPont Company. The papers of du Pont describe both his business activities at E.I. du Pont de Nemours & Company, his family life, and his activities in the Episcopal Church.

Pierre Samuel "P.S." du Pont (1870-1954) was the great-grandson of Eleuthère Irénée du Pont (1771-1834), founder of E.I. du Pont de Nemours & Company, and that company played a major role in P.S. du Pont's life. He is most well-known for developing the preeminent botanical gardens, Longwood Gardens in Kennett Square, Pennsylvania. The P. S. du Pont estate papers document the distribution of physical items from his Longwood estate in Kennett Square, Pennsylvania, in the years following his death.

Longwood Gardens is a series of formal display gardens in Kennett Square, Pennsylvania, that was developed by Pierre S. du Pont (1870-1954) after he purchased the site from the Peirce family in 1906. In 1921 he constructed an extensive network of conservatories which contained plantings from many locales, including species from Africa and South America. This collection consists of two homemade stereographs showing different interior views of the conservatory.

The Natrona Alkali Company was incorporated to hold title to 1,600 acres of sodium carbonate deposits in Natrona County by the descendants of chemist, Lammot du Pont (1831-1884), who developed B blasting powder, using Chilean sodium nitrate and had hoped that the sodium carbonate might become a substitute for imported sodium nitrate in the manufacture of explosives, but the deposits turned out to have no commercial application. The Natrona Alkali Company records are primarily the corporate records related to a second incorporation of the company due to a clerical oversight, the materials date from 1950 to 1980, though there are some documents from the ealier company.

In the spring of 1934 the Senate's Special Committee Investigating the Munitions Industry chaired by Senator Gerald P. Nye (1892-1971) began to examine the role that the munitions manufacturers had played during the First World War. This collection consists of photographs of P. S. du Pont, Irénée du Pont, Lammot du Pont, and A. Felix du Pont testifying before the Nye Committee in September of 1934.

Pierre A. Gentieu (1842-1930) was a long-time employee of E.I. du Pont de Nemours & Company. Gentieu was born in France in 1842. He emigrated to the United States around 1859. He began working for DuPont in 1877. This collection is comprised of images taken by DuPont Company employee Pierre Gentieu from approximately 1880 to 1920. Gentieu's images document the DuPont Company Powder Yards along the banks of the Brandywine River in Wilmington Delaware. The collection documents the surrounding community along the Brandywine including worker's families, du Pont family homes, churches in the area, DuPont Company exposition displays, and other facets of social and work life in the area.

Pierre Samuel "P.S." du Pont (1870-1954) was an industrialist, entrepreneur, and philanthropist. He was president of E.I. du Pont de Nemours & Co. from 1915 to 1919 and chairman of the board of directors from 1919 to 1940. This small collection consists of four Christmas greetings letters from Pierre S. du Pont to Joseph H. Odell (1871-1929), pastor of the First Presbyterian Church of Troy, New York. Odell was the officiant at Pierre S. du Pont and Alice Belin's (1872-1944) wedding on October 16, 1915.

Pierre Samuel "P.S." du Pont (1870-1954) was the great grandson of Eleuthère Irénée du Pont (1771-1834), founder of E.I. du Pont de Nemours & Company, and that company played a major role in P.S. du Pont's life. He is most well-known for developing the preeminent botanical gardens, Longwood Gardens in Kennett Square, Pennsylvania. This item is a matted portrait of P.S. du Pont, autographed on front beneath image area.

A Liberty ship was a World War II EC2 type cargo ship designed for the emergency ship building program. Over 2,700 of these ships were built. This item is a photograph which shows a stern of EC-2 Liberty ship.

Pierre Samuel "P.S." du Pont (1870-1954) was an industrialist, entrepreneur, and philanthropist. He was president of E.I. du Pont de Nemours & Company from 1915 to 1919 and chairman of the board of directors from 1919 to 1940. P.S. du Pont was the great-grandson of Eleuthère Irénée du Pont (1771-1834), founder of E.I. du Pont de Nemours & Company, and the great-great-grandson and namesake of the French economist Pierre Samuel du Pont de Nemours (1739-1817). During the early 1920s, P.S. du Pont became an active collector of Du Pont materials, and bought several important bodies of manuscripts from French dealers. This collection consists of manuscripts he collected that are primarily concerned with Du Pont de Nemours, the Physiocrats, the French Revolution, and the antecedents of the Du Ponts and allied families in France. The collection also contains the Wilmington & Kennett Turnpike Co. records dating from 1811 to 1921 that were acquired by P.S. du Pont from 1919 to 1920 when he purchased the company's stock, widened the road, and turned over its administration to the Delaware State Highway Department.

P.S. du Pont (1870-1954) and Louise du Pont Crowninshield (1877-1958) were second counsins and both had an interest in preservation. In the letter, du Pont suggests Eleutherian Mills and Hagley property be preserved as a historic site.

Pierre Samuel "P.S." du Pont (1870-1954) was president of E.I. du Pont de Nemours & Co. (more commonly known as the DuPont Company or simply DuPont) from 1915 to 1919 and chairman of the board from 1919 to 1940. P.S. du Pont was the great grandson of Eleuthere Irenee du Pont (1771-1834), founder of E.I. du Pont de Nemours & Company. He was also an avid collector of documents on the early history of the du Pont family and the DuPont Company. This collection contains elements which were selected from both company and family papers. The material was lodged in du Pont's Wilmington office for a number of years prior to his death in 1954.

Pierre Samuel "P.S." du Pont (1870-1954) was an industrialist, entrepreneur, and philanthropist. He was president of E.I. du Pont de Nemours & Co. from 1915 to 1919 and chairman of the board from 1919 to 1940. P.S. du Pont was the great grandson of Eleuthere Irenee du Pont (1771-1834), founder of E.I. du Pont de Nemours & Company, and the great-great-grandson and namesake of the French economist, Pierre Samuel du Pont de Nemours (1739-1817). du Pont's personal life is well documented by the photographic collection he left, and it followed certain themes. The greatest of these may be horticultural interests which developed during his creation of the celebrated Longwood Gardens in Kennett Square, Pennsylvania, where he lived. du Pont made many foreign and domestic journeys and recorded his travels. His large extended family is included in this collection. This collection is organized into seven series: Longwood Gardens; Individuals and families; Groups and organizations; E.I. du Pont de Nemours & Company; Trips and vacations; Places; and Culture, society, and service.