1904, Sinclair decided to write a novel to expose the cruel exploitation and oppression of workers by factories. Sinclair worked in a large slaughterhouse in Chicago for seven weeks to collect materials. Later, in Tears and Pain, he completed the documentary novel Slaughterhouse in three months and began to be serialized in magazines.

The protagonist in the book is a newly married couple from Lithuania-Eugis and Ona. They left their hometown with great hope of finding the American dream and found jobs in meat processing plants. Unexpectedly, disasters followed. First Jurgis was injured and unemployed, then Ona was raped by the foreman, and Guiorguis was imprisoned because of work anger. Then his wife died in childbirth and his youngest son drowned. The American dream has become a tragic nightmare. After experiencing depravity and confusion, Guiorguis finally wakes up. At the end of the novel, he becomes a socialist believer.

The influence of Slaughterhouse on social reality is far greater than its artistic contribution. Upton sinclair later quipped: "I tried to impress the public, but I hit them in the stomach." . As soon as this "dung" literature was first written, the sales of meat products in the United States dropped sharply, and Europe cut half of the meat products imported from the United States, and the entire American animal husbandry fell into panic. The inside story of American meat processing industry revealed in the book triggered a strong public response to food safety and hygiene, which directly promoted the passage of 1906 "Pure American Food and Drug Administration Act".