It was white people that also thought it was wrong and got it abolished too. BTW a large majority of those slaves were sold to white men by their own people. Chew on that for awhile will ya...
During the same period that European Christians were involved in the slave trade carrying Africans to slavery in the New World, Muslim Turks were enslaving Christians in the Mediterranean and sometimes in the Atlantic. In 1715 Turkish pirates raided the village where some of my ancestors lived and carried off 24 people whom they sold as slaves. As late as 1815 or 1816 Turks raided the island of Sardinia and took away people to be sold as slaves.