Martin Luther King Jr. is the famous civil rights leader known for advocating nonviolent protest. King played a crucial role in the American civil rights movement during the 1950s and 1960s, promoting equality and justice for African Americans through peaceful demonstrations, speeches, and community organizing. His most iconic moment was his "I Have a Dream" speech delivered during the 1963 March on Washington, where he envisioned a racially integrated and harmonious America. King's commitment to nonviolent resistance was influenced by Gandhi's teachings, and his efforts significantly advanced civil rights legislation, including the Civil Rights Act of 1964 and the Voting Rights Act of 1965.