i imagine speech giving predates Cicero " The hour of departure has arrived, and we go our ways — I to die, and you to live. Which is better God only knows."
Yeah it's handy but Lincoln wasn't succesful cause he gave the Gettysburg address, is Thomas Jefferson famous for speeches? No. He wrote the deceleration of independence though.
Although i do see your point as well
I'd have liked to see those papers, would be very interesting.