Jonathan Harrington Green (1813–1887) was an American gambler, inventor, writer and later reformer of illegal gambling. In his youth, he was a skilled card player who left gambling in 1842, he became an active crusader against illegal gambling. He was responsible for enacting anti-gambling laws in several states.
Green was born in Ohio, but traveled the country, including Mississippi river boats, gambling in his younger days. After leaving gambling, he became a general executive agent of the New York Association for the Suppression of Gambling and, between 1850–51, conducted an exhaustive investigation on illegal gambling operations in New York City. He presented his findings astonishing report on the existence of around 6,000 gambling houses, 200 of these being high-class establishments, as well as several thousand raffling, lottery and policy houses.
He published his memoirs on his gambling days while living in NYC, but moved to Indiana during the Civil War became a captain in the Union Army. He was later employed by the US Secret Service. An amateur inventor, he took out 20 to 30 patents during his lifetime.
He retired to Philadelphia after the war where he lived a quiet life with his wife and became destitute, having to ask for funds to bury her.