Rocky,
I think that S. S. Heard was from Morehouse Parish. In 1860, there was S. Smith Heard living near Bastrop, born about 1807 in Georgia. Living near Lum Grove was S. S. Heard, born about 1829 in Mississippi. I assume the younger man was the son of the elder, but this is only a guess.
I have always assumed (dangerous thing to do!) that the younger man was Col. S. S. Heard, but I'm not positive of this.
Can anyone else provide conclusive evidence?
Tim