A prominent leader during the American Civil Rights Movement known for advocating nonviolent resistance is Martin Luther King Jr.. His philosophy was influenced by the teachings of Gandhi, emphasizing peaceful protests, love, and dialogue as essential tools for achieving racial equality and social justice. King's leadership helped mobilize masses through significant events like the Montgomery Bus Boycott and the March on Washington, where he delivered his famous "I Have a Dream" speech, promoting a vision of unity and harmony among all people.