"It lives and breathes in the light, because it has thousands of unfortunates toiling in the darkness. It lives and has its being in proud liberty because thousands are slaving for it, whose thralldom is the price of this liberty." ― Upton Sinclair, King Coal King Coal (1917) by Upton Sinclair is a novel set during the time of the 1913-1914 coal strikes in Colorado. It is a story that describes the working conditions in the mines as seen through the eyes of its protagonist, Hal Warner. As an avid follower of socialist doctrines, the author chose the story of Warner, an upper-class observer, to expose the exploitation of miners.