"All The Pretty Little Horses" A black wet nurse has to leave her own baby unattended to look after her white ward.

"Massa's In The Cold Cold Ground" Stephen Foster

Not sure of the title but:
"Oh Freedom, sweet Freedom
Freedom is for me.
And before I'd be a slave
I'd be buried in my grave
And go home to the father
And be free."

A young slave, whose mother was promised that her son would be freed, is put up for auction upon her death. But runs away preferring death to slavery. I think I have a recording of this by Ed Trickett but I will have to dig.