"The Ghosts of Cracke Road" by Joyce Hansen

Cracke Road in Charleston, South Carolina was on land that used to be a plantation and it was rumored that when you sang "Sweet Hour of Prayer" you could see the ghosts of slaves that tried to run away. No one believed it until a young girl said a ghost was going to help her reunite with her mother in New York, and sure enough, two weeks after disappearing a letter arrived from New York saying that she was safe and with her mother.