Mark Rothko (1903-1970) is known for his abstract expressionist paintings which are easily recognizable among all the artworks created by 20th century artists. Apart from his well-known large-scale paintings, the artist also created around 3,000 pieces on paper which are just as inventive. CBS News’ chief election and campaign correspondent, Robert Costa, recently visited an exhibition at the National Gallery of Art in Washington D.C., which showcases the extensive collection of paper works left behind by the artist. Robert had the chance to talk to curator Adam Greenhalgh, as well as the artist’s children, Kate Rothko Prizel and Christopher Rothko, about Rothko’s unique and impressive artistic vision.