George Whitefield (1714–1770) began preaching at the age of twenty-four and is the greatest preacher America has ever seen. He preached eighteen thousand sermons to over ten million people during the Great Awakening. He planted 150 churches in New England, New York, New Jersey, Pennsylvania, and Maryland. He preached in open air with crowds as large as thirty thousand people at a time. Amazingly, he preached to such crowds without a microphone and would cough up blood from the strain on his throat. It is estimated that most Americans heard him preach at least once. His farewell sermon on Boston Commons drew more people than Boston’s entire population and was the largest crowd ever gathered in America up to that time.
Taken from Mark Driscoll's Blog