Sinclair was assigned to go undercover in a Chicago meatpacking plant for seven weeks to gather observations about conditions within the plant and to interview local residents to document their accounts. Sinclair later stated that after this experience that he'd become pale and thin because of extreme hunger and because of all of the gruesome images he'd observed. With this information, he felt he could start a revolution and started writing The Jungle.
Despite his best intentions, Sinclair's novel didn't raise support for those working in factories, but rather exposed the unsanitary conditions within meatpacking plants. Even President Theodore Roosevelt read The Jungle and soon after ordered the inspection of the U.S. meatpacking industry, thus resulting in the passing of the Pure Food and Drug Act and the Meat Inspection Act in 1906, which still effect U.S. citizens today.