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.Plimpton subsequently appeared in numerous dramas, including Sidney Lumet's Running on Empty (1988), in which she re-teamed with Phoenix, Woody Allen's Another Woman (1988), Parenthood (1989) — in which she gave a hilarious performance as Dianne Wiest's rebellious, pregnant teenage daughter — and Stanley and Iris (1990), which featured her as Jane Fonda's pregnant teenage daughter. Plimpton continued to work steadily throughout the '90s in a series of films that often featured her in eccentric roles. She did particularly memorable work in Beautiful Girls (1996), playing Michael Rapaport's exasperated girlfriend; I Shot Andy Warhol (1996), which featured her as a lesbian prostitute; John Waters' Pecker (1998), which cast her as the protagonist's sister, a go-go boy recruiter for the local gay bar; and 200 Cigarettes (1998), an ensemble drama in which Plimpton starred as a young woman equally obsessed with Elvis Costello and throwing a successful New Year's Eve party.