Charles Grandison Finney was _the_ figure of the Second Great Awakening. He started off Presbyterian, but he was an odd Presbyterian because he did not like the Westminster Standards. He ended up moving away from Presbyterianism.
In Rochester, New York, there was, all of a sudden, a booming population. Finney went there and started preaching, resulting in massive conversions. He moved to New York City and there were also massive conversions. He finished his life as president of Oberlin College in Ohio and was the main figure of the Second Great Awakening. He also introduced what are called “the new measures” into American evangelicalism.
Probably no figure casts his shadow over American evangelicalism more than Charles Grandison Finney, and—spoiler alert—not necessarily for the good. In fact, it’s for the bad. He is the one who introduced a cooperative effort both in preaching and receiving between man and God for God to work. _In order_ for God to work, it has to be a cooperative effort. This is bad theology. This is bad church practice.
So, Charles Grandison Finney plays that role in American church history.