DD

Dupont De Nemours, Inc.

A specialty chemicals maker producing Tyvek protective garments, water-filtration membranes, medical device components, and building insulation. Founded in 1802 by French-American chemist Eleuthère Irénée du Pont, who set up a gunpowder mill along Delaware's Brandywine River. Fun fact: Tyvek, its famously tough paper-like fabric, was discovered by accident in 1955 when a researcher spotted a mysterious "white fluff" spilling from a lab pipe.