Martin Luther King Jr. played a pivotal role in the Civil Rights Movement as a leader and advocate for nonviolent protest against racial segregation and injustice. He emerged as a prominent figure during the Montgomery Bus Boycott in 1955 and went on to lead various campaigns, including the March on Washington in 1963, where he delivered his iconic "I Have a Dream" speech. King's philosophy was deeply rooted in nonviolence, inspired by Mahatma Gandhi. His efforts contributed significantly to landmark legislative changes, including the Civil Rights Act of 1964 and the Voting Rights Act of 1965, leaving a lasting legacy on the fight for equality and justice.