About the book (from Wikipedia):
The Gangs of New York: An Informal History of the Underworld is an American non-fiction book by Herbert Asbury, first published in 1927 by Garden City Publishing Company.
The book details the rise and fall of 19th century gangs in New York City, prior to the domination of the Italian-American Mafia during Prohibition in the 1920s. Focusing on the saloon halls, gambling dens, and winding alleys of the Bowery and the Five Points district of Lower Manhattan, the book evokes the destitution and violence of a turbulent era, when colorfully named criminals like “Dandy” Johnny Dolan, William Poole (also known as Bill the Butcher), and Hell-Cat Maggie lurked in the shadows, and infamous gangs including the Plug Uglies, Dead Rabbits, and Bowery Boys ruled the streets. It includes a rogues’ gallery of prostitutes, pimps, poisoners, pickpockets, murderers, and thieves.
The book contains detailed accounts of the New York City draft riots in 1863. It also elaborates on numerous other criminal influences of the time, including river pirates and the corrupt political establishment such as Tammany Hall.
The book was loosely adapted into the epic historical drama film Gangs of New York (2002) by director Martin Scorsese.