I'm guessing knife edged too. They could be done either blind or with a blanket or other stitch which could be a contrast or matching tone.
But keep in mind, as soon as there were sewing machines there were people making quilts with them. You can have an entirely machine pieced and quilted civil war era quilt. We quilters (in addition to advanced tool using) are pretty darn clever and as they say, there's nothing new under the sun. Someone could have indeed been birthing quilts long before we would have thought of the idea ourselves
