S. Epatha Merkerson
S. Epatha Merkerson (born November 28, 1952) is a film, stage, and television actor. She has received numerous high-profile accolades for her work, including an Emmy Award, a Golden Globe Award, a Screen Actors Guild Award, four NAACP Image Awards, two Obie Awards and two Tony Award nominations. She is best known for her award-winning portrayal of Lieutenant Anita Van Buren on the NBC police procedural drama series Law & Order, a role she played from 1993 to 2010, appearing in 388 episodes of the series. She is also known for playing Reba the Mail Lady on Pee-wee's Playhouse and Sharon Goodwin in the NBC medical drama Chicago Med since the series premiered in November 2015 (and in crossover appearances on Chicago Fire and Chicago P.D.)
Source: Wikipedia