On April 3rd, 1968, the day before he was assassinated, Martin Luther King gave a speech in Memphis, Tennessee.  Towards the end of his speech, King referenced the story of Moses who led his people out of slavery in Egypt.  When they reached the river Jordon, God took Moses up a mountain and showed him the promise land that lay across the river.  God told Moses that the Israelites would cross over into that land but first he would die.  And so Moses came down from the mountain, gathered his people together and said goodbye.

Complete speech:
I've Been to the Mountaintop

Songs from Civil Rights rallies:

Ain't Gonna Let Nobody Turn Me Round