Back of the Yards is an industrial and residential neighborhood so named because it was near the former Union Stock Yards, which employed thousands of European immigrants in the early 20th century. Life in this neighborhood was explored in Upton Sinclair's 1906 novel "The Jungle". The area was formerly part of the town of Lake until it was annexed by Chicago in 1889. In the late 19th and early 20th centuries, the area was occupied largely by Eastern European immigrants and their descendants, who were predominantly ethnic Bohemian, Moravian, and Slovak.