How many Great Awakenings are there? How have they impacted the United States?

In reading Jonathan Edwards' "Sinners in the Hands of an Angry God", I noticed that his sermon is dramatically different from many preached today. Most churches speak of God's love and limitless mercy in today's world. This made me wonder about how much the Christian world has transformed in the past three hundred years. There must have been other grand revivals in America to have changed the worlds delivered behind the pulpit so dramatically.

Jonathan Edwards is one of the more renowned preachers of the First Great Awakening. He started the preaching style to become associated with the type of sermons given in this era. George Whitefield and the Wesley Brothers are sometimes credited with the beginning of this mass revival. They were the ones to bring a strongly emotional style to their congregations.(http://www.conservapedia.com/First_Great_Awakening)

 
The initial Great Awakening started when some people started preaching of a personal relationship with God. This broke away from the old connection with God. It blocked out the old middle man, the church. Christians began to realize they could determine right from wrong with their consciousness. They no longer found it necessary to talk to a preacher about their questions. The First Great Awakening helped put Americans in the mindset to break away from English rule. The colonists started seeing themselves as Americans for the first time. Many historians credit this great revival with the existence of the United States as a nation. (http://www.great-awakening.com/?page_id=22)

The Second Great Awakening began shortly after the American revolution in the early nineteenth century. The United States was rapidly changing, and many people were uneasy about the sudden changes surrounding them. America's population had increased from five million to nearly thirty million people. Cities were emerging out of the Industrial Revolution. To address these changes the Second Great Awakening spoke strongly of good work ethic and the chances of advancing in rank in society. Along with this came the belief of the American dream and temperance. Anti-slavery groups, feminist groups, and the Civil War are all strongly connected to these great tent revivals of this time period. The realization of equality among all people eventually formed and was reinforced thanks to the sermons of this Great Awakening. (http://www.ushistory.org/us/22c.asp),(http://www.press.uchicago.edu/Misc/Chicago/256626.html)

Most historians agree that these are the only Great Awakenings up to date. There are arguments that there was a third in the early twentieth century, and many people believe we are currently going through one. I disagree, but the whole concept is disputable. The percentage of the World's Christian population is falling. Many people claim to be non-religious. The estimated worldly percentage of this group stands around thirteen percent. Below is Glenn Beck of Fox News arguing his belief on the situation.