During a time in Mexico he was influenced by hearing of the execution squads established by Porfirio Díaz,[citation needed] and became a supporter of Emiliano Zapata.

These influences led him to write a number of labor oriented poems,[citation needed] one of which became the words for the oft-sung union anthem, "Solidarity Forever".

In 1917 Chaplin and some 100 other Wobblies were rounded up, convicted, and jailed under the Espionage Act of 1917 for conspiring to hinder the draft and encourage desertion.

Although he continued to work for labor rights after his release from prison, Chaplin was very disillusioned by the aftermath of the Russian Revolution and the evolution of the Soviet state and international communism, particularly its involvement in American politics and unions in 1920–1948, as he details in his autobiography, Wobbly.

[page needed] Chaplin maintained his involvement with the IWW, serving in Chicago as editor of its newspaper, the Industrial Worker, from 1932 to 1936.