The back of this quilt is much more humble than the front. I think the person who put this together was winging it.
It seems that the quiltmaker found scraps big enough to back the log cabin blocks on the front. Sashing and cornerstones like the front side were added last -they are all topstitched.
The fabrics on the back are clearly clothing remnants or scraps from clothes-making, some stained a bit, some well worn. I see pants and shirts, a flannel shirt and perhaps a nightie, along with some of the brightly flowered bark cloth from the front. Heavier thread was used on the back and the tension didn't work in some sports. There is a little more wear on this side, reflecting how worn the fabrics were.