Since its founding, the American Association of University Professors has been concerned with infringements of academic freedom when colleges interfere with invited speakers. The first time the AAUP seems to have addressed the problem categorically, however, was through a resolution adopted fifty years ago by the annual meeting. The Association took action after the House of Representatives Un-American Activities Committee issued a list of "radical and/or revolutionary speakers" and colleges and universities repeatedly canceled their appearances. The 1957 annual meeting resolution, asserting that "it is educationally desirable that students be confronted with diverse opinions of all kinds," held that "any person who is presented by a recognized student or faculty organization should be allowed to speak on a college or university campus." This article describes how AAUP has been monitoring and categorically opposing the outside-speaker ban since the cold war.