What went wrong? Why did Wesley respond so positively to Benezet's influence and bring a huge number of his followers to bear witness against slavery, yet Whitefield acquiesced to the prevailing view of his age? While we may never know all the answers to these questions, it is possible to trace the thinking of the two men and even read Benezet's evaluation and conclusion on Whitefield's slavery position.
Brendlinger, Irv A., "Wesley, Whitefield, a Philadelphia Quaker, and Slavery" (2001). Faculty Publications - College of Christian Studies. 120.