Martin Luther King Jr., a Baptist minister who pushed for social change through non-violent protest, was the best known leader of the civil rights movement of the late 1950s and the 1960s.

He rose to prominence in December 1955, when he led a boycott of the Montgomery, Alabama, bus system after Rosa Parks was arrested for refusing to give up her seat on a bus to a white person. The boycott lasted 382 days. It led to a United States District Court decision that outlawed racial segregation on buses.

King then fought against racial injustice throughout the country. He traveled an estimated 6 million miles and gave about 2,500 speeches between 1957 and 1968, according to a biography on the web site of the Nobel Prize Committee.

The most famous of those speeches was on Aug. 28, 1963, during the March on Washington. King stood on the steps of the Lincoln Memorial and spoke to thousands of people on the National Mall in what became known as the ”I have a dream” speech.

”I have a dream that one day this nation will rise up and live out the true meaning of its creed ‘We hold these truths to be self-evident, that all men are created equal,”’ King said.

”I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin, but by the content of their character,” he added.

In 1964, King received the Nobel Peace Prize.

On April 4, 1968, King was shot to death by James Earl Ray in Memphis, Tennessee, where he had gone to help black sanitation workers who were on strike. King was 39-years-old.