I became aware of the Federal Writers' Project recently when my daughter was completing a research paper. Her source was a state guide. This government- sponsored project was conducted in the 1930s to provide work for writers, historians, etc during the Depression.
In addition to state guides, there were interviews conducted with former slaves. Two books by Belinda Hurmence that came of the more than 10,000 pages of interviews, conducted with 80 and 90 year olds are called
Before Freedom: When I Just Can Remember and
We Lived in a Little Cabin in the Yard.
The memories of these former slaves are quite interesting, especially considering that they were only 10 or so years old when the Civil War ended.