Marguerite Lammot du Pont Lee (1862-1936) was activist for women's suffrage, child labor, and other social issues. She was the second daughter of Eleuthere Irenee du Pont (1828-1877) and Charlotte Henderson du Pont (1835-1877). She spent her childhood at the family home on Brecks Lane, ‘Swamp Hall’ near the powder mills of which bears her family name.

At age ffifteen, the du Pont was orphaned along with her four siblings when her parents died just over a month apart. Her mother, Charlotte, had been committed to an insane asylum following an attack of hysteria likely brought on when she returned from a trip to Europe in search of a state of better mental health and relaxation to find her children beaten and nearly starved by their nurse. The emotional stress of the incident was too much to handle for the mentally fragile Charlotte. She was taken to an insane asylum, where she died on August 19, 1877. Her husband would die twenty-nine days later on September 17th of consumption, aggravated by exposure from working in the family powder mills.

Leaving five orphaned children and a home owned by the DuPont Company, the family elders planned to split up the five orphans amongst relatives. When word reached Swamp Hall that their uncle Alfred Victor du Pont was on his way to the home to break up the family, the five children took arms, young Marguerite du Pont with a rolling pin, Alfred with a shotgun, Annie with an ax, Maurice a pistol, and Louis a bow and arrow. After much negotiation, a report was made back to the head of the family, Henry du Pont, who yielded and allowed the children to remain in the home under the supervision of the oldest daughter, Annie, along with their loyal house staff.

After leaving Wilmington, young Marguerite met Cazenove Gardner Lee (1850-1912), a lawyer, whom she married on September 20, 1881. Settling in the Georgetown section of Washington D.C., Lee became very involved in social and political affairs. Lee became active in settlement housework in 1898 and built the Kemper Bobcock Memorial in Georgetown. Throughout her life, Lee lectured on capital and labor, liquor, religion, and suffrage.