At the time he visited, public education was rare and voluntary. The first US law mandating attendance at school was introduced in 1852 by Massachusetts, sometime after the reported 90%+ literacy rates were achieved. (I have significant skepticism that it was actually 99.96%, but 90% sufficient to read and write at what we'd consider a grade school level these days, sure.)

Well, extrapolate the data, from a largely rural society where you could get through life without ever reading a single word, and today, where literacy is held in somewhat higher regard, and the effect of mandatory education on literacy rates doesn't look that profound.

I'd say the basic introduction to liberal arts and natural sciences are much better arguments for mandatory education than literacy rates.

996 out of a thousand would be 99.6%, but I agree with your suspicions.

"would be"? You mean it isn't?

(I've been reading http://news.ycombinator.com/item?id=486574 )

There was no public education on any sort of large scale until at least the 1840's, and not really widespread until the reconstruction era government.

That's fascinating. What I was taught about education in that era involved the whole "1 room schoolhouse" thing (which probably says a lot about the quality of the public education I received.)