Martin Luther King Jr. was the prominent civil rights leader known for advocating racial justice and equality in the United States during the 1950s and 1960s. A gifted orator and an advocate of nonviolent protest, King played a pivotal role in the civil rights movement, organizing peaceful demonstrations and marches to combat racial segregation and discrimination. His leadership in events such as the Montgomery Bus Boycott and the March on Washington, where he delivered his famous "I Have a Dream" speech, galvanized public opinion and led to significant legislative changes, including the Civil Rights Act of 1964 and the Voting Rights Act of 1965.