I believe that no man who holds a leader's position should ever accept favors from either side. He is then committed to show favors. A leader must stand alone.
If you want to be fully convinced of the abominations of slavery, go on a southern plantation, and call yourself a negro trader. Then there will be no concealment; and you will see and hear things that will seem to you impossible among human beings with immortal souls.
I think if you get asked to do this, then that's called doing your homework, and I try and do it.

