Actress Rosemarie DeWitt was born on October 26, 1974 in the borough of Queens in New York City. Her first acting experience was during her high school years in New Jersey, where she became an active participant in school plays. She eventually moved on to take a creative studies degree at the Hofstra University in Long Island, New York, and took further training at the Actors Studio in New York City.
DeWitt first earned acclaim as a stage actress. Several of her off-Broadway appearances—including productions of Danny and the Deep Blue Sea, The Butter and Egg Man and Small Tragedy received rave reviews, with her performance in the latter getting particular notice; as part of its cast, she received an Obie Award. It wasn’t soon before she would make the jump to acting for the screen, beginning with a guest role on Law & Order: Special Victims Unit in 2001, and two years later, another guest role in Sex and the City. She went on to appear in several films, notably a small role in Cinderella Man, a biopic based on the life of her real-life grandfather, boxer James J. Braddock.
DeWitt’s first major television role came in 2006, when she became a regular of the crime series Standoff. The short-lived series saw her appear as Emily Lehman, a senior negotiator for the FBI in Los Angeles. The drama suffered a crash in viewers throughout its first season, and was cancelled one episode shy of its initial 19-episode run. The following year, she had a prominent recurring role on the Emmy-winning series Mad Men, appearing as the mistress to lead character Don Draper (Jon Hamm).
More recently, she played a starring role in the acclaimed drama film Rachel Getting Married, which earned rave reviews for her co-star Anne Hathaway. She also took a role in the comedy series The United States of Tara, which premiered in early 2009.