Actor James Earl Jones is famous for his trademark baritone voice, but these days he’s trying to sound like Thurgood Marshall, Lyndon Johnson and others from the U.S. civil rights era.

Jones will star in “Thurgood,” a one-man play at Westport Country Playhouse about the first black justice of the U.S. Supreme Court. Marshall, who died in 1993, successfully argued Brown v. Board of Education, a decision that struck down racial school segregation in 1954, before serving on the nation’s highest court from 1967 to 1991.