In his later years, Dr. Martin Luther King Jr. expanded his focus to include issues of economic justice and opposition to the Vietnam War.

In April 1968, he traveled to Memphis, Tennessee, to support a strike by African American sanitation workers who were protesting poor working conditions.

On April 4, 1968, while standing on the balcony of the Lorraine Motel, Dr. King was assassinated by a sniper.

His assassination sparked an immediate wave of grief and anger across the nation and the world.

Riots broke out in more than 100 cities across the United States in the days following his death.

The assassination was a major blow to the Civil Rights Movement, which lost its most prominent and charismatic leader.

It contributed to a sense of disillusionment and a shift toward more militant factions within the Black Power movement.

James Earl Ray, a career criminal and escaped convict, was convicted of the murder.

Dr. King's legacy as a champion of nonviolent struggle for justice and equality has had a lasting global impact.

His birthday is now observed as a national holiday in the United States.