A dramatic actress of stage, screen, and television, Martha Plimpton has specialized in playing rebellious, eccentric young women. The daughter of actress Shelley Plimpton and actor Keith Carradine (the two never married and split up before she was born), Plimpton was raised by her mother on New York's Upper West Side. She made her acting debut at age eight and her film debut two years later with a bit part in Rollover (1981).
When she was 11, Plimpton appeared in a series of Calvin Klein commercials, but her real break didn't come until Tom Rickman cast her as Tommy Lee Jones' daughter in The River Rat (1984). No sooner had she finished that then she was co-starring in Steven Spielberg's cult classic The Goonies (1985) and the following year in Peter Weir's The Mosquito Coast, which featured River Phoenix among its impressive cast. Though her role in the latter film was relatively small, it went some way toward establishing Plimpton as a serious actress to be watched. The Mosquito Coast also played a vital role in her developing relationship with Phoenix; for a time the two dated seriously, and they remained close friends until the actor's death in 1993.