"...Antietam by the numbers..."
I read once that the Civil War was a series of engagements using 18th century tactics and 20th century weapons. Not an entirely correct summation, but close enough to understand I wouldn't have wanted to be in my great grandfather's shoes at Fredricksburg.
When asked why they were fighting if they disapproved of slavery themselves, a Southerner answered, “Because you guys were here!”
This line may be well known but it still strikes me as both corrective and classic.