In 1802 Eleuthere Irenee du Pont, a French emigrant, purchased 65 acres along the Brandywine River in Delaware and began a gunpowder manufactory. He purchased the land from Jacob Broom for $6,740. By spring of 1804 he offered the first powder for sale. At the prompting of his father, Pierre Samuel du Pont, the manufactory was named Eleutherian Mills. On April 11, 1812 du Pont bought 30 additional acres from Broom's estate to bring the Eleutherian Mills holdings to 95 acres. The second purchase included the area where the family cemetery is located.

E. I. du Pont purchased the Hagley yard property on March 9, 1813, from Thomas Lea, who had obtained it six days earlier from Rumford Dawes. The property on both transactions was referred to as "Hagley, an Estate". When Dawes purchased the site in 1783 that name does not appear on the document of record. By 1797 the property was referred to as "Hagley on the waters of the Brandywine" on an insurance document. It seems evident that
Dawes named the property, but there is no documentation for why he selected Hagley. A book of poetry published just before Dawes purchased the land contained a poem which described an estate in England named Hagley Park. The terrain was similar to the Delaware property, and perhaps Dawes selected the name from the poem. Whatever the source of the name, E. I. du Pont purchased the land to expand operations of the powder manufactory during the War of 1812. By mid century the Hagley yard was referred to as Upper Hagley yard and Lower Hagley yard, but it was one powder yard, its land mass being long and narrow, which might account for the descriptions of upper and lower.

The last yard built was referred to as the Lower Yard or Lower Works. Constructed in 1837, it was located just beyond New Bridge on what is part of today's DuPont Company Experimental Station. Until the black powder works closed in 1921 the total area was frequently referred to by various names such as Brandywine Works or DuPont Works. In the 1870s the mills employed over 300 people. By 1902 the site and equipment were already dated. Improvements were made when leadership of the company changed that year, but the end result was inevitable. Smokeless powder and dynamite had all but replaced black powder, and the narrow scope of the land along the river made efficiency improvements difficult. A serious explosion in 1920 brought all the mounting concerns to a head, and in 1921 production on the Brandywine ceased. The mills closed and houses and land were
sold to du Pont family members.
 

For more information on the E. I. du Pont de Nemours, Inc.