The American civil rights leader who delivered the famous "I Have a Dream" speech is Martin Luther King Jr.. This iconic speech, given during the 1963 March on Washington, emphasized themes of racial equality and justice. King articulated a vision of a society where individuals would be judged by their character rather than skin color. His speech played a pivotal role in galvanizing public support for civil rights legislation and remains a powerful symbol of the movement's aspirations for freedom and equality. King’s eloquence continues to inspire social justice efforts today.