Unglamorous but distinctive, both in her talent and down-to-earth appearance, Merkerson started out on stage, appearing off-off Broadway and in regional theater. In the '80s, she landed her first series-regular TV role as Reba the mail lady on Pee-wee's Playhouse, and essayed a handful of guest spots. She seemed destined to become one of the legions of working no-name actors, until everything changed for her in the '90s. After being nominated for a 1991 Tony for her searing turn in the Pulitzer Prize-winning play The Piano Lesson, Merkerson turned in a devastating performance as a grieving mother in a Law & Order episode. The next year, she again worked with Law & Order creator Dick Wolf on the short-lived sci-fi crime series Mann & Machine, on which she played a cop. So when Law & Order introduced no-nonsense police lieutenant Anita Van Buren in Season 4, Merkerson was a shoo-in for the part. In addition to her high-profile gig, she took on small roles in features and TV-movies, and regularly returned to her theatrical roots. But in 2005, a different small-screen project brought her the most success to date: her turn as the lively head of a boardinghouse in the TV-movie Lackawanna Blues, which earned her myriad accolades, including an Emmy, a Golden Globe, a SAG Award and an NAACP Image Award.