Martin Luther King Jr. (1929-1968) was an American civil rights leader, minister, and advocate for racial equality. He played a pivotal role in ending racial segregation and advancing civil rights for African Americans through nonviolent protests and civil disobedience. His most famous speech, "I Have a Dream," delivered in 1963, became a symbol of hope for millions. King was awarded the Nobel Peace Prize in 1964 but was tragically assassinated in 1968.