Originally Posted by Kat Sews
Black is more reliable now than it was during the civil war. Black used in their quilts was usually wool or silk because they would hold the dye and not fade as quickly. If you are going for authenticity you might want to re-think black cotton.
This was my thoughts, also. They leaned toward brown & indigo (inky/navy blue sort of) if they wanted dark cotton fabric. If you used actual civil war repro fabrics to make the quilt. If you just made the blocks with whatever fabric you wanted, then the Kona Black would also be my suggestion.