AbstractThe author compares the development of university libraries in Europe and in the United States of America. She finds that the university libraries in the United States of America have developed for three centuries under the influence of the European libraries, but now in the last century the European libraries have developed under the influence of the American ones. In times when there were no professional librarians, the American university libraries were managed by university professors, who were educated at European universities. The European management patterns were consequently applied also to the American libraries. The first books were also first brought from Europe. The Humboldt university also had a strong influence on the development of the American university libraries. Not until the second half of the 19th and especially the 20th century did the American university libraries achieve such high levels of cataloguing, classification, co-operation, organisation, computer networks, information holders, education and constructing library buildings that the European libraries started assuming their methods.