Slender, cross-eyed and handsome, George Whitefield was an Anglican priest and powerful orator with charismatic appeal. At the age of 25, he created a sensation in England by preaching outdoors and going over the heads of other priests to reach their congregations. In 1740, he brought that same defiance of authority to America, along with a savvy sense of the media. Newspaper ads announced his sermons; messengers rode ahead to spread the news of his coming appearances.

In one year, Whitefield traveled 5,000 miles through America, preaching more than 350 times as he traversed the nation North to South. An estimated 25,000 people gathered on Boston Common to hear him speak. Another 12,000 heard him in Philadelphia and 8,000 in New York City. In 15 months, as much as a quarter of the country had heard his message.

Whitefield was a staunch Calvinist. His central theme -- what must I do to be saved? -- was not new. His preaching style was. Ministers traditionally wrote sermons in longhand and read the text out loud in a dull monotone. The effect was often soporific. Drawing on his youthful foray into drama, Whitefield memorized his sermons, spoke without notes, varied the timbre of his voice and gestured with abandon. He drew freely on his own emotions, crying out, "My Master! My Lord!" It was said that he could utter the word "Mesopotamia" so that the entire crowd wept. The effect was electric. Crowds responded with outpourings of emotion. People cried, sobbed, shrieked, swooned and fainted. All of New England, it seemed, was seized by a spiritual convulsion.

Whitefield ignited the Great Awakening, a major religious revival that became the first major mass movement in American history. At its core, the Awakening changed the way that people experienced God. Instead of receiving religious instruction from their ministers, ordinary men and women unleashed their emotions to make an immediate, intense and personal connection with the divine. From New England to Georgia, the revival was marked by a broad populist tone -- small farmers, traders, artisans, servants and laborers were especially swept up by the preaching of Whitefield and his followers. As historian Harry Stout observed: "They were still part of a view of the world as a world divided between superiors and inferiors. And you had to know your place. And if you didn't know your place order would break down and all chaos would ensue. ... Whitefield smelled the dissolution of the old aristocratic order. He saw that what had been was not what was going to be."

At first, established ministers had welcomed Whitefield and his fellow revivalists. Church attendance swelled. New energy was in the air. Soon, however, the clergy realized that the revivalists were challenging their authority. Itinerant preachers like Whitefield could preach anywhere; they did not need a church. Ignoring parish boundaries, they lured crowds away from the pews and into the fields. Once the revivalist ministers stirred up the populace, they were free to move on. Their emotional style disrupted the usual social decorum.

By 1742, an acrimonious debate about the Great Awakening had split the New England clergy into rival factions. The "Old Lights" opposed preachers like Whitefield; the "New Lights" supported them. Whitefield himself appeared to have second thoughts about the religious movement that he had ignited. But it was too late. Although the energy of the First Great Awakening subsided in the late 1740s, revivals became a persistent feature of the American religious landscape.