Who is Boss Tweed from Reconstruction: America's Unfinished Revolution, 1863-1877 and what is their importance?

William "Boss" Tweed was a political operator in New York City. He is greatly remembered for defrauding millions of dollars from the city. Some of the money was used to assist immigrant families. Tweed also controlled the appointment and elections of city officials. In the end, he was prosecuted by Samuel Tilden, who later went onto run for President of the United States.