Upton Sinclair's The Jungle was first presented to the public in 1906. The author is a journalist who likes to write in the genre of political fiction. This particular book is dedicated to the working immigrants who had to go through harsh conditions and mistreatment in Chicago and other industry-based cities. However, despite Sinclair's attempt to show the public that you can't treat the immigrants as slaves and that the whole system needs to change, the majority of readers paid a lot more attention to the unsanitary practices in the meatpacking industry.
It even lead to a national outcry that made a lot of changes happen. Obviously, the author of the book was a bit disappointed with the public reaction and the fact that they didn't really care about the main message of the book. He once said to the public that all he wanted to do was to touch the hearts of the American people, but, instead, he touched their stomachs.
Still, The Jungle is a fundamental work and depicts poverty and unpleasant living conditions that the working class has to deal with. They've got no social support and no hope for the future. The author talks about the corrupted folks in power and calls people to action against this unfair system, and later on the critics called him a muckraker (a person who manages to expose corruption in the government elite).
The book's hero, Mr. Rudkus, is an immigrant who's trying to make an honest living in the States. He starts working at a slaughterhouse, but, due to the harsh working conditions, he and his young wife barely keep it all together. They owe a lot of money and get evicted from their house. Eventually, life in America leads them to moral and physical degradation and even the kids start to work in order to survive.