Upton Sinclair (1878-1968), a self-described socialist propagandist, was a prolific American author and trailblazing social crusader who sought to uncloak the "wage slavery" of workers by pioneering investigative journalism known as "muckraking." His 1906 exposé The Jungle blew the whistle on deplorable sanitary and labor conditions in the U.S. meatpacking industry, triggering a thunderous public outrage that contributed to the swift passage of both the Pure Food and Drug Act and the Meat Inspection Act. Following the Ludlow Massacre - the seminal event of the 1913-1914 Colorado Coalfield War, and a strike identified as "one of the most grueling, long-lasting industrial conflicts in the history of the United States" - Sinclair focused his reformer attention on the coal mining industry with his 1917 novel King Coal, wherein the fuse ignites when Hal Warner relentlessly organizes a strike to help fellow coal miners unionize against a corrupt and exploitative coal baron, erupting in an explosive climax.