We learned that the early Americans rarely (if at all) used glass in their windows.
(I'm sure many other places did this too, but we are studying early Americans at the moment.)
They used oiled paper.
We oiled our own paper to see why.
Oiled paper is stronger than dry, it is more see-through, and it repels water.
When glass was not readily available, oiled paper was the stuff.
I LOVE that I learn along with the kids!