Mary Dempsey is a notable figure known for her contributions to the field of library science. She served as the Commissioner of the Chicago Public Library, where she implemented various initiatives to enhance community access to information and resources. Her leadership focused on improving library services and promoting literacy among diverse populations. In addition to her role in Chicago, Dempsey has been involved in various professional organizations related to libraries, such as the American Library Association. She has also participated in numerous conferences and workshops, sharing her expertise and advocating for the importance of libraries in society.