Upton Sinclairs The Jungle is a vivid portrait of life and death in a turn-of-the-century American meat-packing factory. A grim indictment that led to government regulations of the food industry The Jungle is Sinclairs extraordinary contribution to literature and social reform. Upton Sinclair was a Pulitzer Prize--winning author. The Jungle helped in the passage of the pure-food laws during the Progressive Era.