Educated at the University of Missouri school of drama, Cooper has appeared on Broadway in "Of the Fields Lately (1980)", off-Broadway in "The Ballad of Soapy Smith (1983)" and "A Different Moon (1983)". He debuted in films in the John Sayles movie Matewan (1987). Although his performance was well received, the picture was not successful. Other films he has appeared in include Guilty by Suspicion (1991), Money Train (1995) and A Time to Kill (1996). On television, Cooper has been featured in the mini-series "Lonesome Dove" (1989) and "Return to Lonesome Dove" (1993), as July Johnson. He has also appeared in a number of Television Movies. In 1996, he appears in his third John Sayles movie Lone Star (1996), where he plays Sam Deeds, the sheriff whose lawman father becomes a posthumous suspect in a murder investigation.