Here is an excellent quote from (as Mark Noll says) Rev. Anyabwile:
The earliest black Christians maintained a tendency toward a Reformed or orthodox view of God as sovereign Ruler of all events. African-Americans built this understanding upon the teachings of Scripture and aligned it with the historic definitions of Christianity. A high view of God's sovereignty allowed early black Christians, despite the horrors of slavery, to trust that God had the necessary power to deliver them from oppression and that he would ultimately do so. Any perceived contradictions between this doctrine of God and the evil afflicting black people were resolved in the character of God. Such a belief implied at least two conclusions. First, these saints concluded that the events of their lives remained in the sovereign control of God. And second, they concluded that the proper response before the ineffable wisdom and providence of God was humility and faith. Both resolutions stirred more faith in God (p. 97).