The American civil rights leader known for his nonviolent approach was Martin Luther King Jr.. He advocated for racial equality through peaceful protests and was a prominent figure in the civil rights movement of the 1950s and 1960s. King's famous speeches, including the "I Have a Dream," galvanized public support for civil rights and highlighted the injustices faced by African Americans. His leadership and commitment to nonviolent resistance played a crucial role in achieving significant legislative changes, such as the Civil Rights Act of 1964 and the Voting Rights Act of 1965.