American Methodism in 1780s

Slavery was an critical issue for John Wesley, and he criticized slavery in many ways–sermons, letters, and writings, 'Thoughts upon slavery'. His concern on slavery originated from his visiting to America, Georgia and South Carolina. He witnessed immorality and inappropriateness of slavery. This idea was conveyed to Asbury. "American Methodism" quotes Asbury's saying regarding slavery: "I am strongly persuaded that if the Methodists will not yield on this point and emancipate their slaves, God will depart from them." Thus, it is obvious that both Wesley and American Methodists strongly opposed to slavery.

However, Allen, who experienced conversion through a sermon from a Methodist circuit rider when he was a slave, disappointed with American Methodism in 1780s, and he "founded African Methodism to recapture authentic Wesleyanism in America." In the article, "Richard Allen: A Quintessential Wesleyan," Dickerson mentions that "during the 1780s, Methodism changed…the fervor with which the gospel was advanced, openness to the poor and to blacks that once had been the norm in Methodist societies, and the staunch abolitionism that had been a trademark of Wesleyan preachers all started to wane." I think the 1784 Christmas Conference brought huge alteration into American Methodism.

I was wondering why Methodism in America suddenly changed, why American Methodists at that time diminished their zeal against slavery, and what happened at the Christmas Conference.