In 1913–1914, Sinclair made three trips to the coal fields of Colorado, which led him to write "King Coal" and caused him to begin work on the larger, more historical "The Coal War." In 1914, Sinclair helped organize demonstrations in New York City against Rockefeller at the Standard Oil offices. The demonstrations touched off more actions by the Industrial Workers of the World (IWW) and the "Mother Earth" group, a loose association of anarchists and IWW members, in Rockefeller's hometown of Tarrytown.