In 1983, President Ronald Reagan signed a bill creating a federal holiday to honor Martin Luther King, Jr. Now, 30 years later, every state celebrates Martin Luther King, Jr. Day. Google is also celebrating the day, with a very artistic Doodle on the frontpage of their search engine.
Google first celebrated the memorable day back in 2003, and has continued doing so from 2006 - 2013. You can find all of the King's Doodles in the Doodle Archives.
Martin Luther King, Jr.
Martin Luther King, Jr. was an American clergyman, activist, and leader in the African-American Civil Rights Movement. He is best known for his role in the advancement of civil rights using nonviolent civil disobedience. Wikipedia