To protect his young son from the tumult of the Republican period, he sent Antoine home to the family estate in Winterthur, where he spent his boyhood.

In 1801, Bidermann and other French investors funded son Éleuthère Irénée du Pont's new gunpowder factory on Brandywine Creek in Delaware.

In 1814, the French investors sent Antoine Bidermann to investigate, bearing letters of introduction from the Marquis de Lafayette to Thomas Jefferson and Bushrod Washington.

[1][2] As his father-in-law's sole business partner from 1815 to 1834, Bidermann oversaw the accounts, purchased supplies, arranged sales, and managed personnel.

Bidermann paid off the company's debts and bought out the French shareholders, making the du Pont family the full owners.

He constructed a three-story Greek Revival mansion of his own design,[3] planted extensive gardens and orchards, bred livestock, and developed a model farm and dairy.

[2] Passed down through the family, the estate became the Winterthur Museum, Garden and Library in 1952 and "houses one of the nation's outstanding collections of furniture and the decorative arts.