The Socialist Propaganda League of America was established in 1915, apparently by C.W. Fitzgerald of Beverly, Massachusetts. The group was a membership organization established within the ranks of the Socialist Party of America and is best remembered as direct lineal antecedent of the Left Wing Section of the Socialist Party and its governing National Council — the forerunner of the American Communist movement.
In the fall of 1915, C.W. Fitzgerald wrote and sent a leaflet to Vladimir Lenin of the Russian Social Democratic Workers Party. Lenin replied, outlining his views on the situation faced by the revolutionary socialist movement.
It was not until November 1916 that any sort of broad-based organization was established. A November 26, 1916, meeting in Boston approved a first manifesto for the organization and established an official journal, The Internationalist. The paper was launched in Boston at the start of January 1917 and continued under that name through April of that year. The initial editor of The Internationalist was John D. Williams.
According to the group's constitutional objectives, "The SPLA declares emphatically and will work uncompromisingly in the economic and political fields for industrial revolution to establish industrial democracy by the mass action of the working class."
In January 1917, editor Williams traveled to New York City in order to raise money for the Socialist Propaganda League and its newly launched paper. Williams made the acquaintance of a young Italian-American radical named Louis C. Fraina, until recently a key editor at the now-defunct magazine The New Review. Williams sought an experienced editor to take over the publication and a compact was made.
Beginning with an issue dated April 21, 1917, The Internationalist was moved to New York City and published by the Socialist Propaganda League as The New International. Louis Fraina became the publication's editor at that date. The publication was financed through donations made by Dutch engineer and left wing socialist S.J. Rutgers. Circulation was small, estimated by historian Theodore Draper at "no more than a thousand copies of each issue," which served to limit the paper's influence. Nevertheless, Draper and other historians of the American left regard The Internationalist and its successor as the first propaganda organs of the movement which congealed as the Left Wing Section of the Socialist Party in 1919 — forerunner of the American communist movement.