Answer
The works of Upton Sinclair, notably his famous novel "The Jungle," often spotlighted the lives and struggles of industrial workers, shedding light on the harsh working conditions and societal challenges they faced. Sinclair's writings exposed the exploitation and injustices experienced by laborers, particularly in the meatpacking industry, and aimed to raise awareness and provoke social change to uplift the working class during the Progressive Era in the United States.