Tammany Hall, also known as the Society of St. Tammany, the Sons of St. Tammany, or the Columbian Order, was an American political organization founded in 1786 and incorporated on May 12, 1789, as the Tammany Society. It became the main local political machine of the Democratic Party and played a major role in controlling New York City and New York state politics. Though initially an independent social organization, at its peak, Tammany Hall became synonymous with the New York County Democratic Party.
At its founding, the Society of St. Tammany was a social fraternal organization and one branch of a network of Tammany societies throughout the new United States of America. Politically, its members were Jeffersonian republicans opposed to the Manhattan aristocracy. As the immigrant population of New York grew, Tammany Hall became an important social and political organization, for Irish Catholic immigrants in particular. Following the 1854 mayoral election and the resulting mayoralty of Fernando Wood, Tammany Hall controlled Democratic Party nominations and political patronage in Manhattan for over a century through its organized network of loyal, well-rewarded, and largely Irish Catholic district and precinct leaders. It also gained support from the New York City business community for its efficient, if corrupt, solutions to problems.