I wouldn't be surprised if an 8th grade education wasn't the average level of education in those days. Or even lower. What was the level of literacy for the entire population at the turn of the century? It might surprise us to find out. I know I was once shocked to read somewhere that a third of the population of Shakespeare's London knew how to read and write. Not bad, considering the crushing poverty of the time, and the fact there was no school system. Education was such a rare gift it was not squandered then as it is now.

One of the things I remember about Ken Burns' Civil War series was the incredible literary quality of the letters the soldiers wrote home. Granted, those letters were selected, and have survived, precisely because they were of superior quality, but still, compare it to similar collections of letters from our more modern conflicts.

Now that you've brought this up, I've often wondered what should be the baseline level of education, the bare minimum the society should guarantee its children. Here is my opinion, and I say opinion because there is no way to prove or disprove this.

Assuming starting kindergarten at age 5, by age 10 a child should be literate enough to read a newspaper or popular magazine, and write a logically consistent, grammatically correct and properly spelled essay summarizing what he has read,, and do arithmetic up to the level of multiplying and adding fractions and converting to decimals and back.

By age 15, the child should have read and understood about a hundred standard literary works of his country and the world, and have a basic understanding of the outline of national and world history, and his own country's political organization. He should be able to write a formal coherent essay. He should have an elemental working knowledge of geography; world, national and local, and a knowledge of science (by science, I mean the kid should be able to explain things like why we have seasons, what atoms are, the basic description of the solar system, and how we know bacteria cause disease). By this time, the child should understand mathematics up to the level of geometry, algebra and trigonometry. A substantial portion of today's college graduates would fail this test.

College should be reserved for learning a profession, not for general education (although much general education can and should be acquired there). Still, we shouldn't be doing remedial training at the university. I think it is important all college graduates be qualified in some discipline, some field of human knowledge or investigation. They may never actually use it in their work, but they need to be exposed to a solid introduction to something, so they'll know what a "solid introduction" really means. I may not know squat about medieval French literature, but I know what it would take to be knowledgeable about it. The college degree, for those not fortunate enough to actually work in their major, should prove you have the ability to learn a profession. By age 20, you should be out of college, unless you are entering into specialized graduate work. I was 30 before I finally left the University.
Granted, I had accomplished a few other things during that time, but that's still too long.

I also think there are other things an education should provide. A educated person should speak at least one foreign language. I do, but I take no pride or credit for it. I learned it as a child, and young children absorb languages effortlessly. I failed in my efforts to learn ancient Greek and French as an adult. The first because I was too lazy to really make the effort, the second because I was too lazy to take advantages of my many opportunities to follow up and build on what I learned in the classroom. I'm ashamed to admit at one time I could translate technical papers from French to English, and today I cannot understand the headlines of the Quebec newspapers at the local stupormarket.

The other thing I believe is essential to an education which I totally lack is a knowledge of music, both in how to play an instrument, and read the notation. There is a whole universe closed to me, and I regret that I never took the opportunity to learn. No excuses, I was just too lazy.