The Ludlow massacre happened September 1914, during a strike pitting the United Mine Workers against the Colorado Fuel and Iron Company, which was owned by the Rockefellers. The miners and their families were kicked out of company houses, and in order to continue the strike they set up a tent camp outside of Ludlow. 15 people were killed by machine gun fire, and the burning of the tent camp. During the entire strike thirty three people were killed and many more seriously injured. As a result of Ludlow and a strike a couple years later in New Jersey, Rockefellers hired Mackenzie King, who later became Prime Minister in Canada, to establish the first "company unions". The workers responded by establishing the Oil Workers International Union, which effectively counterposed the company unions and eventually merged with the Gas Coke and Chemical Workers, in 1955 to become the present day Oil Chemical and Atomic Workers Union. I don't recall how old Woody might have been in 1914, but knowing the folk process and Woody's political identification, it is clear he wrote another outstanding song, displaying his understanding of both issues and people.