Martin Luther King Jr. was an influential civil rights leader and activist in the United States. He was a key figure in the American civil rights movement, advocating for nonviolent protest and civil disobedience to bring about social and political change. King is best known for his role in the advancement of civil rights using the tactics of nonviolence and civil disobedience based on his Christian beliefs and the teachings of Mahatma Gandhi. He is most famous for his "I Have a Dream" speech, delivered during the March on Washington for Jobs and Freedom in 1963. King was awarded the Nobel Peace Prize in 1964 for his efforts to combat racial inequality through nonviolent resistance. His legacy continues to inspire people around the world in the ongoing fight for equality and justice.