The SNPJ was formed in Chicago, Illinois on April 6, 1904, and held its first convention on April 9. The society was organized the result of a call in a Slovenian language newspaper for a new Slovenian benefit society. The founding twelve delegates represented nine independent Slovene groups with a total membership of 276. The organization was incorporated on June 17, 1907. The incorporation was delayed over a year because of an Illinois law which required fraternal benefit groups to have at least 500 members. In 1905 membership had grown to over 1,500 in 27 lodges. By only 1907 there were almost 4,300 members in 60 lodges. In 1917 the SNPJ, with 16,700 members in 360 lodges, had become the largest Slovene fraternal benefit society in the United States.