According to several historians, the armies that fought in the Civil War were the most literate armies in history up until sometime right around the year 2000
The battle of Gettysburg had a total of 200,000 combatants. Lee had 75000 men, and the Union forces had 94,000 men. Citation. The battle of Passchendaele had 800,000 dead, wounded or captured alone. 3 million troops fought in total in the American Civil War. There were over 38 million dead, wounded or missing combatants in World War 1, and that doesn't even count how many participated. We're talking orders of magnitude more soldiers, obviously some of them were dumb as fuck.