Complex sentence: He takes time to discuss how those who he visited that did not take care of their slaves he felt uncomfortable there, and that individuals who did take care of their slaves made him feel more at ease.
Split into simpler sentences: He takes time to discuss those who he visited that did not take care of their slaves and how that made him feel uncomfortable while visiting. In contrast, Woolman discusses individuals who did take care of their slaves and how that made him feel more at ease.