Butler technically didn't do anything, it was done by Truman and Bernard Baruch. The final solution is the name given to the order of a mass killing of all the Jews, exterminating by force through gas chambers or shootings, when all else failed they resulted to this.
It would be under the circumstance that "<span>Congressional leaders believe they have the votes necessary to override a veto," since otherwise it would be seen by many as being a waste of time. </span>
A. multiple voices i believe
The group that was brought over was African Slaves to replace the Native Americans