Amazingly enough dynamite was actually a safety improvement over highly volatile nitroglycerine which was under heavy use at the time. Dynamite could be used for the many earthworks efforts of the time, not only in mining but also in clearing away stubborn mountains that stood in the way of a railroad’s intended route.
On the other hand, the convenient nature of dynamite also expanded its use in killing large groups of people in a single effort and was viewed by many as one of the first (arguably) true weapons of mass destruction.
Before his death, a paper accidentally carried his obituary which basically remembered him as a modern harbinger of death due to his horrific creation.
Le marchand de la mort est mort ("The merchant of death is dead")
it went on to say, "Dr. Alfred Nobel, who became rich by finding ways to kill more people faster than ever before, died yesterday.”
Not wanting this to be his legacy, the Nobel Prize was essentially his effort to "rebrand" himself and on 27 November 1895, Nobel signed his last will and testament, setting aside the bulk of his estate to establish the Nobel Prizes.
Did it work?
Before reading this, were you aware of Nobel’s original notoriety?