Sesame Street's cast expanded in the 1970s, better fulfilling the show's original goal of greater diversity in both human and Muppet characters. The cast members who joined the show were Sonia Manzano (Maria), who also wrote for the show,[118] Northern Calloway (David), Alaina Reed (Olivia), Emilio Delgado (Luis), Linda Bove (Linda), and Buffy Sainte-Marie (Buffy).[119] In 1975, Roscoe Orman became the third actor to play Gordon, succeeding Hal Miller, who had briefly replaced Matt Robinson.[120]