Sean Justin Penn (born August 17, 1960) is an American actor, screenwriter and film director, also known for his left-wing political and social activism (including humanitarian work). He is a two-time Academy Award winner for his roles in Mystic River (2003) and Milk (2008), as well as the recipient of a Golden Globe Award for the former and a Screen Actors Guild Award for the latter. Penn began his acting career in television with a brief appearance in a 1974 episode of Little House on the Prairie, directed by his father Leo Penn. Following his film debut in 1981's Taps and a diverse range of film roles in the 1980s, Penn emerged as a prominent leading actor with the 1995 drama film Dead Man Walking, for which he earned his first Academy Award nomination and the Best Actor Award at the Berlin Film Festival. Penn received another two Oscar nominations for Sweet and Lowdown (1999) and I Am Sam (2001), before winning his first Academy Award for Best Actor in 2003 for Mystic River and a second one in 2008 for Milk.