1791–1883, American inventor, industrialist, and philanthropist, b. New York City. After achieving success in the glue business, Cooper, with two partners, erected (1829) the Canton Iron Works in Baltimore. There he constructed the Tom Thumb, one of the earliest locomotives built in the United States. His success in trials on the Baltimore & Ohio RR probably saved that pioneer line from bankruptcy.
During the next 20 years, Cooper expanded his holdings, becoming a leader in the American iron industry, and in 1870 he was awarded the Bessemer gold medal for rolling the first iron for fireproof buildings. Cooper invented and patented other practical devices and processes. His faith in the success of the Atlantic cable led him to invest heavily in the New York, Newfoundland, and London Telegraph Company after banks refused to finance the operation. He was president of this company for 20 years while he headed the North American Telegraph Company, which controlled more than half of the telegraph lines in the country.
An outstanding leader in the civic affairs of New York City, Cooper led the successful fight to secure a public school system and did much to improve several of the municipal departments. His lasting monument is Cooper Union in New York City, built after his own plans to provide for education for the working classes. He supported the Greenback party in national politics, and in 1876 he was the party's presidential candidate, polling over 80,000 votes. Many of his addresses were collected in Ideas for a Science of Good Government (1883, repr. 1971). Abram S. Hewitt was his son-in-law, Peter Cooper Hewitt his grandson.