He arrived nearly penniless and believed soap and salvation were related. William Colgate boiled his first batch on a narrow Manhattan street in 1806; ninety years later his company put toothpaste in a collapsible tube and taught a whole country to brush — alone, twice a day, from a tube with one name on it. It is the rare brand in this series that was never swallowed by a larger combine: more than two centuries on, Colgate still trades under its own name, owned by no one above it. Here is how a Baptist soap maker’s promise became the daily ritual of a nation.

A French immigrant came home from a hunt in 1800 angry about his gunpowder, and two centuries later the company he built had given the country nylon, Teflon, Kevlar, and the suit that walked on the moon — and a chemical in nearly every bloodstream on earth. DuPont turned powder into chemistry, and chemistry into the very texture of modern life. This is the story of the laboratory that engineered the American future, and the cost the country is still paying for it.