[wirrbel]

I don't write that much about making excel spreadsheets. I'd assume that when they stumbled over a rock they put it on the side of their field, arranging it to a wall. They might have just wrote down "field work" in diaries (if they had the time to write).

[foxhop]

You don't write about spreadsheets, but if we look at the library or the internet we can see that at least one person writes about spreadsheets.

There is not one piece of written evidence that the colonists created all the walls. There is not one piece of written evidence that the native Americans built the walls.

We don't know who built the walls.