Its a very divisive topic now, but I'm curious if this is relatively new. Like, did people protest public hangings for moral reasons? Was it something people debated and had an opinion about?
I was thinking that maybe people were just more exposed to death in general, so the idea of dying for your crimes wasn't so extreme.
There has been debates over death penalty for quite some time. Just list a few examples: San Marino did not execute any more prisoners after 1468. Thomas More's Utopia, published in 1516, debated the benefits of the death penalty but did not give a conclusion. Anton Chekhov short story The Bet written in 1889 centers around two people's argument over death penalty, etc.
While I'm certainly no expert on the subject, I do know that in 1764 Cesare Beccaria published On Crimes and Punishments in which he condemned capital punishment. He basically argued that capital punishment had no real benefit to society and did not deter crime.