The Second Great Awakening was a Protestant Christian movement in the late 1700s and early 1800s. It was a series of revival meetings that took place all across America. Traveling preachers led groups of people in worship and preached a personal response to God and a return to Biblical teaching. It involved less formal expressions of worship, such as dancing or shouting, and more emotional responses to the teaching than "traditional" services.
People from many church groups were involved. The Methodists were especially organized in sending out preachers; the Baptists were also highly involved.
The Second Great Awakening resulted in higher church attendance and a higher level of racial equality in some parts of the church. For example, a black preacher named Harry Hosier ended up preaching to white congregations. (Remember that this was over 60 years before the Civil War and over 160 years before the Civil Rights Movement.)
It also resulted in the formation of more Bible societies and other Christian organizations to provide Bibles and teaching for new Christians and greater female involvement in the church.
Hope this helps; I don't tutor students in history, but I'm drawing from what I remember and from internet resources.