During the Gilded Age of the late 1800s, political machines formed in many large cities. Political bosses would offer services and favors to citizens and businesses in exchange for votes and political power. While some bosses, like Roscoe Conkling, used the system to help citizens through projects like hospitals and schools, many bosses engaged in corruption. Common corrupt practices included kickbacks, where contractors building public projects would illegally return part of the payment to the political boss. A notorious example was William "Boss" Tweed in New York City in the 1860s-1870s, who took over $13 million in kickbacks from contractors on a courthouse that only cost $3 million to build.