•Why it earns a slot
Why it earns a slot: it is the rare novel that changed law on contact, Roosevelt read it, ordered his own investigation into the packinghouses, and signed the Pure Food and Drug Act the same year, for a reason Sinclair himself resented: "I aimed at the public's heart, and by accident I hit it in the stomach."
Sinclair set out to indict wage slavery in the Chicago stockyards and instead triggered a meat-inspection law, because readers cared more about what was in the sausage than about the men grinding it.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.