Wednesday marks 50 years since assassination of Dr. Martin Luther King Jr.

Wednesday marks 50 years since the assassination of Dr. Martin Luther King Jr.

When Martin Luther King Jr. was killed on a hotel balcony in Memphis, a movement lost its leader - and four children also lost their father.

King was killed April 4, 1968. The loss has not gotten easier in 50 years for his three surviving children.

The siblings cling to the few memories they have of him. At times, they have been reluctant and angry to mourn him and share his legacy and death with the rest of the world.

Their anger has at times spilled into the public eye and courtrooms, but they come together in times of tragedy.

The tributes to their dad are points of pride, but also constant reminders of the void left by his death.

In honor of his legacy, take a look back at inspiring quotes from the civil rights leader and pastor.

"Injustice anywhere is a threat to justice everywhere." (Letter from Birmingham City Jail)

"We must use time creatively, in the knowledge that the time is always ripe to do right." (Letter from Birmingham City Jail)

"The ultimate measure of a man is not where he stands in moments of comfort and convenience, but where he stands at times of challenge and controversy" (1963 book Strength to Love)

"Oh, there will be a day, the question won't be, 'How many awards did you get in life?' Not that day ... The question that day will not be, 'What kind of automobile did you have?' On that day the question will be, 'What did you do for others?'" ("The Three Dimensions of a Complete Life" sermon)

"Mankind must put an end to war or war will put an end to mankind." (Oberlin College commencement)

"I have decided to stick with love. Hate is too great a burden to bear." (Where Do We Go From Here, 1967)

"If a man hasn't discovered something he will die for, he isn't fit to live." (Preview of the "Dream" at Detroit March)

"As long as there is poverty in this world, no man can be totally rich even if he has a billion dollars." ("The American Dream")

"Civilization and violence are antithetical concepts." (Nobel Prize Acceptance Speech)

"Everybody can be great ... because anybody can serve. You don't have to have a college degree to serve. You don't have to make your subject and verb agree to serve. You only need a heart..." ("The Drum Major Instinct," Ebenezer Baptist Church)

"Somewhere we must come to see that human progress never rolls in on the wheels of inevitability. It comes through the tireless efforts and persistent work of dedicated individuals..." (Oberlin College Commencement)

"If you can't fly, run; if you can't run, walk; if you can't walk, crawl; but by all means keep moving." ("Keep Moving from this Mountain" address)

ABC News and the Associated Press contributed to this report.