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DuPont's Brandywine gunpowder mills
founded 1802 (Wilmington, Delaware)· Arms maker, factory or program· Arms makers & war industry
Well documentedSolid records, physical evidence or scientific consensus.
Water-powered gunpowder mills on Delaware's Brandywine Creek that grew into DuPont, America's leading explosives maker.
See it on the Battles & Wars map →What happened
Éleuthère Irénée du Pont, who had learned powder making under the French chemist Lavoisier, left revolutionary France and founded the mills near Wilmington in 1802. The stone mill buildings had three thick walls and a light side facing the creek, so explosions blew out toward the water. Blasts still killed over 200 workers across the mills' history, dozens in 1818 alone. DuPont supplied the US in the War of 1812, the Civil War and later wars. The mills closed in 1921.
Why it matters
Gunpowder made DuPont rich enough to become one of America's biggest chemical companies. Its World War I profits fed the 1930s 'merchants of death' debate over arms makers.
How we know
Company and government records, and the Hagley Museum, opened on the mill site in 1957, which preserves the mills, the du Pont home and the company archives.
Still debated
How much DuPont's dominance came from skill rather than the price-fixing 'Powder Trust' it led, until an antitrust suit forced a breakup in 1912, is debated.
Connections (3)
▸DuPont's Brandywine gunpowder mills supplied much of the Union's gunpowder in the American Civil WarMostly agreed
The connection
DuPont was the North's biggest gunpowder maker. Henry du Pont, a West Point graduate, helped keep Delaware, a slave state, in the Union. In late 1861 his nephew Lammot secretly bought large stocks of saltpeter, a key ingredient, in Britain. The Brandywine mills ran at full capacity throughout the war.
When and how
Brandywine Creek, near Wilmington, Delaware, 1861–65; Henry du Pont and Lammot du Pont, supplying the Union Army and Navy.
How sure are we?
Company records at the Hagley Library and government purchase records; exact shares of Union powder are uncertain.
Debates and open questions
Estimates of DuPont's share of Union powder vary widely; the saltpeter purchase was nearly lost when the Trent Affair led Britain to ban exports.
▸DuPont's Brandywine gunpowder mills grew into a leading Allied powder maker in World War IMostly agreed
The connection
When war began in 1914, Britain, France and Russia ordered huge amounts of smokeless powder. DuPont built vast new plants, such as Hopewell, Virginia, and by 1918 had supplied roughly 40 percent of the Allies' military propellant. Its workforce and profits soared, and the profits later drew the 1934 Nye Committee hearings on arms makers.
When and how
DuPont plants in Delaware, New Jersey, Virginia and Tennessee, 1914–18, for Britain, France, Russia and, from 1917, the US.
How sure are we?
Company and government records, and the Nye Committee's published hearings; the 40 percent figure comes mainly from company sources.
Debates and open questions
The share depends on what is counted, powder or all explosives; whether the profits were fair or 'war profiteering' was hotly argued in the 1930s.
▸DuPont's Brandywine gunpowder mills grew into the company that built and ran Hanford Site (plutonium production)Well documented
The connection
The company born at the Brandywine gunpowder mills had become a chemical giant by 1942. At General Groves's request, DuPont designed, built and ran Hanford's reactors and plutonium plants, scaling Fermi's experimental reactor up enormously. Stung by 'merchants of death' charges after World War I, it took a fee of just $1.
When and how
DuPont's Wilmington, Delaware, headquarters and Hanford, Washington, 1942–1946; DuPont engineer Crawford Greenewalt with Manhattan Project scientists; General Electric took over in 1946.
How we know
Manhattan District contracts showing the $1 fee, DuPont company records at the Hagley Museum, and declassified Hanford histories.
Debates and open questions
Credit between DuPont's engineers and the physicists is still weighed; extra fuel tubes DuPont insisted on rescued B Reactor from 'xenon poisoning' in 1944.