The People of the Abyss (1903) is a book by Jack London about life in the East End of London in 1902. He wrote this first-hand account by living in the East End (including the Whitechapel District) for several months, sometimes staying in workhouses or sleeping on the streets. The conditions he experienced and wrote about were the same as those endured by an estimated 500,000 of the contemporary London poor.
There had been several previous accounts of slum conditions in England, most notably The Condition of the Working Class in England in 1844 by Friedrich Engels. However, these were second hand sources and not based upon first hand study. Jack London was a very successful man, and his account was far more popular.