One of the interesting tidbits I picked up from reading the Slave Narratives at the Library of Congress was the use of Pine knots. The knots of pine trees were used as a candle substitute when the slaves ran out of candles or lamp oil.
There were other curious tidbits I picked up from the slave narratives that I'll share in the future. This project was done between 1936-1938. I include the information here because it is from interviews with former slaves. The project was published in 1941 and you can find most of them at the Library of Congress online today. It's a great resource for historians and novelist.
A fair amount of the interviews are recorded and you can hear them as well.