The United States came into existence as a result of religious conflicts. The difficulty, for American society as for libraries, consists in identifying the separation between Church and State and in defining “religion”. The American right does not interfere in these problems and occupies itself solely with defining the minimal acceptable response. Libraries, microcosms of society, constitute one of the frontiers drawn between State and citizens. Following the example of other public places, they allow the guaranteed rules of social harmony to be tested. They perceive themselves as meeting-places. The American Library Association is actively involved in the defence of intellectual freedom.