I have some Alice in Wonderland fabric that my mom bought in the 70's to make a baby blanket for me, and she never made it so she just gave the fabric to me when I was a teenager. I'm still holding onto it for something special, though I did use some of it for my first nephew's first baby quilt.
It's not quilting cotton though, more of a lightweight denim/canvas type fabric.
As for fabric I've purchased myself, probably nothing older than the late 90's, but I'm not certain.