While he is still a peasant boy in Lithuania, Jurgis Rudkus falls in love with a gentle girl named Ona. When Ona’s father dies, Jurgis, planning to marry her as soon as he has enough money, comes to America with her family. Besides the young lovers, the emigrant party is composed of Dede Antanas, Jurgis’s father; Elzbieta, Ona’s stepmother; Jonas, Elzbieta’s brother; Marija, Ona’s orphan cousin; and Elzbieta’s six children. By the time the family arrives in Chicago, they have very little money. Jonas, Marija, and Jurgis at once get work in the stockyards. Dede Antanas tries to find work, but he is too old.
They decide that it will be cheaper to buy a house on installments than to rent. A crooked agent sells them a ramshackle house with a fresh coat of paint that he describes to his ignorant customers as new. Jurgis finds his job exhausting, but he thinks himself lucky to be making forty-five dollars a month. At last, Dede Antanas also finds work at the plant, but he has to give part of his wages to the foreman in order to secure his job.
Jurgis and Ona save enough money for their wedding feast and are married. Then the family finds that they need more money. Elzbieta lies about the age of her oldest son, Stanislovas, and he, too, gets a job at the plant. Ona is already working. Dede Antanas works in a moist, cold room, where he develops consumption. When he dies, the family has scarcely enough money to bury him. Winter comes, and everyone suffers in the flimsy house. When Marija loses her job, the family income diminishes. Jurgis joins a union and becomes an active member. He goes to night school to learn to read and to speak English.
At last, summer comes with its hordes of flies and oppressive heat. Marija finds work as a beef trimmer, but at that job the danger of blood poisoning is very great. Ona has a baby, a fine boy, whom they call Antanas after his grandfather. Winter comes again, and Jurgis pulls a tendon in his ankle while attempting to avoid a rampaging steer at the plant. Compelled to stay at home for months, he becomes moody. Two more of Elzbieta’s children leave school to sell papers. When Jurgis is well enough to look for work again, he can find none, because he is no longer the strong man he was. Finally, he gets a job in a fertilizer plant, a last resort, for men last only a few years at that work.
One of Elzbieta’s daughters is now old enough to care for the rest of the children, and Elzbieta also goes to work. Jurgis begins to drink. Ona, pregnant again, develops a consumptive cough and is often seized with spells of hysteria. Hoping to save her job, she allows herself to be seduced by her boss, Connor. When Jurgis learns what she did, he attacks Connor and is sentenced to thirty days in jail. Having time to think in jail, Jurgis sees how unjustly he is treated by society. No longer will he try to be kind, except to his own family. From now on, he will recognize society as an enemy rather than as a friend.
After he serves his sentence, Jurgis goes to look for his family. He finds that they lost the house because they could not meet the payments and moved. He finds them at last in a rooming house. Ona is in labor with her second child, and Jurgis frantically searches for a midwife. By the time he finds one, Ona and the child are past saving. Now he has only little Antanas to live for. He tries to find work. Blacklisted in the stockyards for his attack on Connor, he finally finds a job in a harvesting machine factory. Soon after, he is discharged when his department closes down for a lack of orders.
Next he goes to work in the steel mills. In order to save money, he moves near the mills and comes home only on weekends. One weekend he comes home to find that Antanas drowned in the street in front of the house. In order to flee his inner demons, his remorse, and his grief, he hops a freight train and rides away from Chicago. He becomes one of the thousands of hobos and workers; his old strength comes back in healthful, rural surroundings.
In the fall, Jurgis returns to Chicago. He gets a job digging tunnels under the streets. Then a shoulder injury makes him spend weeks in a hospital. Discharged with his arm still in a sling, he becomes a beggar. By luck he obtains a hundred-dollar bill from a drunken son of a packing owner. When he goes to a saloon to get it changed, however, the barkeeper tries to cheat him out of his money. In a rage, Jurgis attacks the man. He is arrested and sent to jail again. There he becomes acquainted with a dapper safecracker, Jack Duane, whom he met during his last incarceration. After their release, Jurgis joins Duane in several muggings and becomes acquainted with Chicago’s underworld. At last, he is making money.
Jurgis becomes a political worker. About that time, the packing plant workers begin to demand more rights through their unions. When packinghouse operators will not listen to union demands, there is a general strike. Jurgis goes to work in the plant as a scab and is given a managerial position. One night, however, he meets Connor and attacks him again. After getting out on bond and learning that Connor is well connected, Jurgis flees from the district to avoid a penitentiary sentence. On the verge of starvation, he finds Marija working as a prostitute. Jurgis is ashamed to think how low he and Marija fell since they came to Chicago.
Jurgis leaves, despondent, but he happens upon a socialist meeting. He experiences something like a religious transformation. At last, he knows how the workers can find self-respect. He finds a job in a hotel where the manager is a socialist. It is the beginning of a new life for Jurgis, the rebirth of hope and faith.