The purpose of this Master?s thesis is to describe and analyse the development of the public and the study circle libraries in the district of Kolbäck during the period of 1913-1954. The factors important for the library development described in sub-questions are: financing, locality, staffing, stock of books, book-lending level and uniting district effects. I use a hermeneutic interpretation model of interaction between the parts and the wholes, between reasons and results. This research leans mainly upon material which is sent to be deposited in archives in Hallstahammar, Västerås and Grängesberg.