- Founded what would become Chicago's Steppenwolf Theatre Company in 1974 with his high-school friends Gary Sinise and Terry Kinney, and served as its artistic director in the 1980s.
- Met first wife, Laurie Metcalf, when both were theater students at Illinois State University.
- Made movie debut in Remember My Name, a 1978 drama produced by Robert Altman; appeared in The Wedding (directed by Altman) later that year.
- Has appeared on some 40 TV series, including Columbo, Family Ties, thirtysomething, L.A. Law, Frasier, NYPD Blue, ER, The West Wing, Lost, Prison Break, Cold Case, C.S.I: Crime Scene Investigation and CSI: New York.
- Was a regular on CBS's Nash Bridges (1996-2001)
- A semiregular on Grey's Anatomy (he plays Meredith Grey's father, Thatcher), he's married to series casting director Linda Lowy.