Which actress won an Oscar for playing Erin Brockovich?

Which actor won an Oscar for playing Idi Amin in 'The Last King of Scotland'? Which actor won an Oscar for playing Winston Churchill in 'Darkest Hour'? Which actress won an Oscar for playing Queen Elizabeth II in 'The Queen'? Which actress won an Oscar for playing Queen Anne in 'The Favourite'? Which actress won an Oscar for 'Million Dollar Baby'? Which actress won an Oscar for 'Monster' (2003)? Which actress became the first Black woman to win the Academy Award for Best Actress, for 'Monster's Ball'? Which actress won an Oscar for playing June Carter Cash in 'Walk the Line'?