Jackson Pollock was one of the most famous american painters of the 20th century. He was mainly focused on abstract expressionism and made his paintings with unique style called drip painting.
You can read more about him HERE.
Official website dedicated to Pollock: http://www.jackson-pollock.org
Here are some of the images Pollock had made during his life. Source: http://www.jackson-pollock.org/jackson-pollock-paintings.jsp