Ella Reeve Bloor was one of the founders of the Communist Labor Party of America, which stemmed from the Left Wing Section of the Socialist Party. In 1921 and 1922, Bloor attended the second conventions of the Comintern in Moscow. She was also a delegate to the founding convention of the Red International of Labor Unions in July 1921, at which she used the pseudonym "Emmons" and voted on the basis of credentials issued by three locals of the International Association of Machinists. Upon her return from the Soviet Union, Bloor hitchhiked throughout the United States while writing articles for the "Daily Worker".