Jack Daniels (the company) confirmed that this is more than likely. Unfortunately, there is little to no documentation on the major impact slaves had on the American whiskey/ distillation industry. See an article about this in the New York Times.
Black History Month Craft: African American Inventors - Set of 6
Charles Baker Inventor L S Radiator March 1877 – July was an African American inventor and community leader most noted for inventing the gas mask, a traffic signal and a hair-straightening preparation.