The thesis deals with the role and development of Public libraries with a focus on the political debate between 1899 and 1912. Public libraries today have a role as a socially important institution and are thus an important part of our society. In order to understand and gain clarity about today's Public library debate and the Public libraries' institutional role and legitimacy, the debate that prompted the development of Public libraries around the turn of the century in 1900 needs to be examined and elucidated. The thesis will deal with the background to the political library debate that took place between 1899 and 1912, how the arguments put forward for the library's development and role in society were and what parallels can be drawn to a contemporary context. The empiric consists mainly of political documents from the Parliament debate and these are analyzed on the basis of an institutional theoretical approach through a qualitative content analysis. Valfrid Palmgren's investigation and report, which was presented in 1911-1912, became important for the development of the Public library and may thus conclude the historical context. The result of the thesis shows a Public library development that follows the prevailing social development in a society where the people's voices through popular movement work, popular education and commitment worked towards democratic goals. The Public libraries came to be important for both the development of that time and have so also today through their today institutional role in society.