I've been reading some letters sent home to families or lovers of Civil War soldiers and I'm astounded by how eloquent and sophisticated they are. From my understanding most of these soldiers barely had any formal education, the majority being farmers or laborers, but they wrote so beautifully. Can anyone give us an understanding of why this is so?
Here's a link to some good examples of Civil War era letters written by soldiers.
"Writing beautifully" seems to be a fairly subjective opinion - you could ask if the writing seems beautiful because of the poignancy of the situation: that the men writing could be killed before the letter arrived etc.
There's also the fact that historians will be apt to select letters that are noteworthy for some reason, either because of the quality of the writing or because the letter-writer supports some salient point of the historian's thesis. So, the letters that you see are more likely to be the "highlight reel"; there could be plenty of dross that isn't worth digitizing.
However:
The USA, especially the North, was actually a pretty decent place to live if you were white - by the standards of the mid-19th century. James McPherson goes into quite some detail on this point in his seminal history of the Civil War, Battle Cry of Freedom: IIRC the only places with better literacy rates than the Northern USA at that time were Norway, Denmark, and Sweden. There was also very much a political awakening, especially by Northern soldiers, who voted overwhelmingly for Lincoln in 1864, and so a lot of them would have been reading Douglass and Greeley etc, and they'd definitely have read Lincoln's speeches when they were published. Improving one's own vocab and writing skills after being exposed to more literary stuff is a well-attested phenomenon.
Could someone check out the literacy rates from the era? Maybe all of the letters were well-written because the only literate people were well-educated?