King Coal (Barnes & Noble Digital Library)

Published in 1917, and based on the Colorado Coal Strikes of 1913-14, this novel is a scathing expose of the conditions in the coal mines of the western United States.  Wealthy Hal Warner comes to investigate the mines under an assumed name.  There he meets Mary Burke and finds himself falling in love with this young champion of worker's rights, even though he must stay emotionally focused on the condition of the miners.