Who played Solomon Northup in '12 Years a Slave'?

Who played Abraham Lincoln in 'Lincoln'? Who played Margaret Thatcher in 'The Iron Lady'? In which film is King George VI a character? Who played Stephen Hawking in 'The Theory of Everything'? In which film is Solomon Northup a character? Who played Cooper in 'Interstellar'? In which film is Cooper a character? Who played Tony Lip in 'Green Book'?