Note that the link you provided doesn't even attempt to argue that literacy rates were as high back then as they are now, it acknowledges the opposite.
Funny I don't recall arguing about that there. I was talking about the literacy of the smart fraction. To quote from the link:
In the extensive NAAL survey, only 13% of adults attained this level. Thus, the proportion of Americans today who are able to understand Common Sense (13%) is smaller than the proportion that bought Common Sense in 1776 (20%).
It seems proportionally more Americans bought Common Sense than could understand it today properly according to the educational metric given. Now people buying material they can't understand for various reasons isn't that uncommon and of course the inference we draw from a particular survey may be problematic for various reasons. But the sheer size of the proportion is pretty striking and decent evidence that literacy among clever people was at the very least not much worse than today and was plausibly perhaps even better.
Yes, but he reaches that conclusion on extremely tenuous grounds.
“search, comprehend, and use information from continuous texts,” is categorized into four levels: below basic, basic, intermediate, and proficient. Proficient, the highest level, is defined as “reading lengthy, complex, abstract prose texts as well as synthesizing information and making complex inferences.” As an example of this level of performance, they cite comparing the viewpoints in two texts. This level seems to be roughly the level required to read Common Sense.
Seems on what basis?...
If it's worth saying, but not worth its own post, even in Discussion, it goes here.