Tammany Hall is the name that is used to refer to the urban political machine that dominated New York City politics at various times in the city’s history. William M. (“Boss”) Tweed was the main figure in Tammany Hall during the late 1860s and early 1870s. The scandal that brought Tweed down began with corruption in the building of a new courthouse and was given greater momentum by a riot between Protestant and Catholic factions of Irish in New York.
Urban political machines were prevalent in American cities beginning in the mid-1800s. They continued to dominate some cities well into the second half of the 20th century, which Chicago’s machine continuing to function into the 1970s. These machines used immigrant votes as their base of power. They kept immigrants happy with patronage jobs and social services and they kept elites happy because they suppressed dissent and controlled the poor of the cities. The members of the machines generally used their offices to enrich themselves and their cronies.
The Tweed scandal came about when Tweed and others used the construction of a new courthouse in Manhattan as a way to make money. The courthouse ended up costing many times what it should because people were being given large amounts of money for little work. For example, the link below tells us that a plasterer got the equivalent of almost $2 million in today’s money for 2 days work. Perhaps most amazingly of all, a report by a committee that was supposed to be figuring out why the courthouse was taking so long to build was published at a cost (in today’s money) of over $100,000. That money was paid to a publishing company owned by Tweed.
This sort of corruption was not particularly new. However, this time, it ended up bringing Tweed down because of a riot between Catholic and Protestant Irish in 1871. The elites of the city felt that the riot proved Tweed was not controlling his immigrant constituents well enough and they decided he had to go. He was eventually convicted of crimes related to corruption and spent the last years of his life in and out of jail.