Jmf: First Great Awakening = mass religious revivalism in the American colonies in the mid-18th century, preachers like Jonathan Edwards (Sinners in the Hands of an Angry God). It's usually hailed as the first cultural event that is really a product of the American Colonies.
Much less interesting to me than the Second Great Awakening (1820s-1840s), which gave us Millerism->Adventism, Mormonism, mass spread of Methodism, Baptism...much more colorful.
As for the Thrid and Fourths?