My husband's aunt showed me once how they carded the cotton. She was from Arkansas and had a lot of raw cotton growing in nearby fields. Wads of cotton bolls we placed along the long edge of one card and then they combed the cotton by pulling the 2 cards apart, handles opposite. This was done several times to make the fibers lay straight and parallel with each other. Then, they would comb the cotton off the card by pushing the 2 cards together. The fibers would roll up along the long edge and then the roll would be placed on the quilt. Once enough rolls were laying on the quilt, side by side, they would pat them all together and start quilting.
I tried it. It's not easy and I can certainly see why they quilted lines so close together. The aunt is gone now.... she was the coolest lady..... but I still have a couple of the quilts she made before WWII. I cherish them. Those ladies worked from sun up to sun down, trying to do things for their families with never a thought of themselves.