A brief outline of the plot
Lured away from their rural Lithuanian home by promises of the good life, the Rudkus family arrive in Chicago at the end of the 19th century only to find out that their dreams of a decent life are not likely ever to come true. Right from the start they have to make compromises and concessions in order to be able to survive. They fall prey to con men who cheat them out of their house so that they have to move to unbearable lodgings. Contrary to their original plan, each member of the family -- whether very old or very young, even if they are suffering from a serious illness -- has to get a job and contribute to the meagre family income. They are faced with a cruel world of work in the Chicago stockyards, where everyone has their price, where everyone in a position of power, including government inspectors, the police and the judges, "takes graft", and where blacklisting is common. A series of unfortunate events -- accidents at work, a number of deaths in the family which under normal circumstances could have been prevented -- more and more lead in the direction of catastrophe. Jurgis Rudkus, young and strong but illiterate, gradually loses all hope of ever succeeding. His brief episode as a hobo in rural America after having left his family only teaches him that there is really no escape, not even outside the city slum where he has been living.
Towards the end of the novel, Jurgis happens to meet some socialist orators and agitators and can finally be convinced by them that socialism, together with strong labor unions, is the only answer to all the evils he, his family and all their fellow sufferers have had to endure. As the reader never learns if Jurgis Rudkus does eventually succeed, Upton Sinclair was criticized for the apparent lack of a proper ending to the novel.