His marxist sympathizing mom.
While Arabs and African chiefs were the greatest of slave traders, it took white Christians, who actually read the words of Jesus, to campaign, speak out and hide away slaves that escaped.
Simple Quakers and Methodists, who felt personally responsible to Jesus for how they walked and talked. The author of 'Amazing Grace', himself a trader, was converted and championed an end to selling humans.
That is History and fact, but we are surrounded by racists that find the Truth to much for them.