Frankel's direction of the off-Broadway production of Jean Genet's "The Blacks" was regarded as a crucial production in promoting African-American theater during the civil-rights movement which opened in 1961 and ran at St. Mark's Theatre for more than 1,400 performances, the longest-running Off-Broadway non-musical of the decade. The cast included James Earl Jones, Roscoe Lee Browne, Louis Gossett, Jr., Cicely Tyson, Godfrey Cambridge, Maya Angelou and Charles Gordone; sets were by Kim E. Swados, music by Charles Gross, and costumes and masks by Patricia Zipprodt.