Martin Luther King Jr. was a prominent civil rights leader born on January 15, 1929, in Atlanta, Georgia. He advocated for nonviolent protests against racial discrimination and is best known for his 'I Have a Dream' speech during the 1963 March on Washington. King greatly influenced civil rights legislation and received the Nobel Peace Prize in 1964. He was assassinated on April 4, 1968, leaving a lasting legacy for equality and justice.