The Jugoslav Socialist Federation was established in Chicago, Illinois, in 1905. The founders were Slovenian, Croatian, and Serbian representatives of several independent socialist and liberal organizations. They represented, in education, socioeconomic class and philosophy, the broad range of South Slavic immigrant America. Although not all Marxist, they were unified in opposition to industrial capitalism and the intrusion of organized religion into economic and political spheres. They also believed in the importance of ethnic awareness and inter-ethnic cooperation among workers. These people established a myriad of organizations in America between 1900 and 1918, among them the Slovenska Narodna Podporna Jednota, the South Slavic cooperative movement, and the Jugoslav Republican Alliance.From 1905 until 1914, the Jugoslav Socialist Federation was the primary political organizaton among South Slav immigrants, dedicated to advancing socialist causes and to enriching the cultural life of its members. From 1912-1917, the Federation was affiliated with the Socialist Party of America; it favored entry of the United States into World War I.

In 1919, it was expelled from the Socialist Party and most of its Serbian and Croatian members joined the Communist movement. Most of the Slovenian membership remained independent, but sympathetic to the Bolshevik Revolution. In 1922, the Federation reaffiliated with the Socialist Party and remained so until 1940. From 1940 until it ceased to exist in 1952, it functioned as an independent socialist and cultural organization, mostly comprised of Slovenians. The Federation published two newspapers, Proletarec (Slovenian) and Radnicka Straza (Serbo-Croatian) as well as an annual, Ameriski Druzinski Koledar. Majski Glas was the May 1st issue of Proletarec, which became a separate publication.