Tammany Hall, (also called the Society of St. Tammany, the Sons of St. Tammany, or the Columbian Order), named for Tamanend (meaning "affable"), a Native American leader of the Lenni Lenape, was started in 1786 and was declared on May 12, 1789 as the Tammany Society. It was the Democratic political machine that played a major role in controlling New York City politics. It also helped many immigrants, especially the Irish, rise in American politics. In 1858 Boss Tweed became its leader. In the middle 20th century it became less powerful and dissolved in the 1960s.