Coal Kingdom by Upton Sinclair is a novel that reflects the harsh reality of miners in the United States during the early twentieth century. The story revolves around Hal Warner, a young man who travels under an assumed name to a coal camp in North Valley, Colorado, to discover the harsh conditions faced by the workers. Sinclair explores the challenges Hull faces, from working in a risky environment to fighting for workers' rights against corporate exploitation. The novel deals with themes such as social justice, corruption, and the struggle of the working class, making it a poignant and challenging experience that workers face in order to improve their lives.