"In the earlier days of freedom almost every colored man who learned to read would receive 'a call to preach' within a few days after he began reading. At my home in West Virginia the process of being called to the ministry was a very interesting one. Usually the 'call' came when the individual was sitting in church. Without warning the one called would fall upon the floor as if struck by a bullet, and would lie there for hours, speechless and motionless. Then the news would spread all through the neighborhood that this individual had received a 'call.' If he were inclined to resist the summons, he would fall or be made to fall a second or third time. In the end he always yielded to the call. While I wanted an education badly, I confess that in my youth I had a fear that when I had learned to read and write well I would receive one of these 'calls'; but, for some reason, my call never came."
Source: Booker T. Washington, Up From Slavery (1901).