Wrong State and time frame for my William Copeland, but have you tried the military records, at the time of liberation, the male slaves could (in some cases pressed into service) join the Union Military (those records are fairly complete). Check Pension applications if any served in the military they would be eligible for a Veteran pension. Look at the years (5-10) after the war was over, some ex-slaves actually did receive the "40 acres + a mule" that they were promised, the Land Bureau keep really good records. I do not know if ex-slaves were required to make an "Oath of Allegiance" or not, the white confederate men and some women did, but that might be a source. I hope this helps give you some more places to look, join the Harris Co Genealogy Society and your local as well, wonderful sources, fantastic help in most, Good Luck.