In March of 1968, King came to Memphis to support striking African-American sanitation workers who were demanding better working conditions and facing massive resistance from white city officials. He was assassinated on April 4, 1968 -- days before he was to lead a march in Memphis. The night before he was killed he gave his "I Have Been to the Mountaintop" speech.

• Dr. Martin Luther King: "Let us develop a kind of dangerous unselfishness. One day a man came to Jesus; and he wanted to raise some questions about some vital matters in life. At points, he wanted to trick Jesus, and show him that he knew a little more than Jesus knew, and through this, throw him off base. Now that question could have easily ended up in a philosophical and theological debate. But Jesus immediately pulled that question from mid-air, and placed it on a dangerous curve between Jerusalem and Jericho. And he talked about a certain man, who fell among thieves. You remember that a Levite and a priest passed by on the other side. They didn't stop to help him. And finally a man of another race came by. He got down from his beast, decided not to be compassionate by proxy. But with him, administering first aid, and helped the man in need. Jesus ended up saying, this was the good man, this was the great man."