The prints look like feed sacks. Printed Feed Sacks can be dated back to 1927 and as recent as 1942 (from Feed Sacks by Edie McGinnis) They came in a varity of sizes. There were also printed flour sacks which were of a finer weave. Some one said, some of us probably have fabric 10 -15 yo. I have feed sacks so I have fabric 50 plus years old.
The blocks are pretty. I hope you do something with them.