The Montgomery bus boycott was a political and social protest against the policy of racial segregation on the public transit system of Montgomery, Alabama. The campaign lasted from December 5, 1955 -- the Monday after Rosa Parks, an African-American woman, was arrested for refusing to surrender her seat to a white person -- to December 20, 1956, when the federal ruling Browder v. Gayle took effect, and led to a United States Supreme Court decision that declared segregation on buses to be unconstitutional.

Delivered to over 250,000 civil rights supporters from the steps of the Lincoln Memorial in Washington, D.C., the speech was a defining moment of the civil rights movement.

According to the King Center, the civil rights leader went to jail 29 times. He was arrested for acts of civil disobedience and on trumped-up charges, such as when he was jailed in Montgomery, Alabama, in 1956 for driving 30 miles per hour in a 25-mile-per-hour zone.

In 1957, King and other civil rights activists founded the Southern Christian Leadership Conference (SCLC). The group was created to harness the moral authority and organizing power of black churches to conduct nonviolent protests in the service of civil rights reform.

At 35 years of age, the Georgia-born minister was the youngest person ever to receive the award.

MLK Day is observed on the third Monday of January each year, which is around King's birthday, January 15.

The inspiration for the memorial design is a line from King's "I Have A Dream" speech: "Out of the mountain of despair, a stone of hope."

Time magazine saw King as the personification of the Civil Rights Movement, and in its January 4, 1964 issue, gave him Man of the Year honors for 1963.

In 1968, King was planning a national occupation of Washington, D.C., to be called the Poor People's Campaign, when he was assassinated on April 4 in Memphis, Tennessee.

The campaign for a federal holiday in King's honor began soon after his assassination in 1968. President Ronald Reagan signed the holiday into law in 1983, and it was first observed three years later, in 1986.