Thank you for all your posts here Homer. I don't comment often on them but I always try to read through them.
The percentage of Americans literate in 1858 was certainly lower than today. There was, perhaps, an interest in longer speeches on key issues, a longer attention span.
Stephens made a mistake in criticizing Lincoln by name and then agreeing to debates. He should have ignored him. Instead, he made Lincoln nationally famous. Would Stephens have become President? Would he have lived past 1861? We will never know.