According to Wikipedia,
William Robert Sickinger was an American theater director, based in Chicago. He was regarded as the founder of "off-Loop" theater, the Chicago equivalent of Off-Broadway. He often cast non-professional actors in his productions, and in doing so occasionally found new talent such as David Mamet, Marilu Henner, Jim Jacobs, and Mike Nussbaum, all of whom were Sickinger proteges.
Robert Sickinger is affiliated with the following schools: