The purpose of this qualitative history thesis is to study how working class people used libraries in 1840–1920. Year 1840 is chosen on the basis that libraries were founded on large quantities in 1840s and 1850s. First library that offered literature in Finnish to working class was founded by Juho Pynninen in 1846. Year 1920 is chosen so that Finnish civil war could be included in the thesis. Research goal is to find what independent opportunities working class had, when they searched information with the help of libraries. Working class libraries were important to working class people and the quantity of working class libraries grew strongest between years 1906–1910. The foundings of Socialist workers party in 1899 and Socialist democracy party in Finland 1903 increased the demand of working class libraries even more. Common libraries had mainly literature about religion, household and other practical subjects which only was seen suitable to commoners.

The language question is essential to the history of common libraries and the decision to choose Finnish helped whole library movement. Finnish language rose to the equal status as Swedish, which molded Finnish identity strongly. Finnish literature was condition to the peoples sophistication. Second condition was the reading skill of common man, which lead to the founding of Finnish school system. Working class libraries were option to common libraries because they compete against censorship and were usually established by workers.

Reseach is based on literature containing history of Finland, history of Finnish common libraries and history of Finnish working class libraries.