Lillie Mae Russell Lamar

I need help finding info on my grandmas ancestry. I can't find nothing on her. Her name was Lillie Mae (maiden name: Russell) Lamar. She was married to my grandpa James Lamar. I have trouble finding anything past my grandpas living with his divorced mother Beulah Long Lamar. I can't find her husband who could be my grandpas dad.My grandpa was dark skinned and had people burning a cross in his yard when he lived in Alabama, so he may not have been the husband of Beulah. However his last name was Lamar.