Tammany Hall, 14th Street (east of Union Square), New York City, USA. Tammany Hall was a New York City political organisation founded in 1786 and incorporated on May 12, 1789, as the Tammany Society. It was the Democratic Party political machine that played a major role in controlling New York City and New York State politics and helping immigrants, most notably the Irish, rise up in American politics from the 1790s to the 1960s.