Wikipedia (which tends to be better sourced these days than it once was) offers a good discussion on the subject, but I also found this snapshot of the religious landscape of the colonial era:
Early New Englanders generally practiced congregationalism, though by the 18th century they seldom thought of themselves as the spearhead of the Reformation. A wave of revivals known as the Great Awakening swept New England beginning in the 1720s, dividing churchgoers into New Light (evangelical Calvinists) and Old Light (more moderate) wings. An increasing minority were calling themselves Baptists.
Nearly all Europeans in these colonies were Protestants, but individual denominations were very different. There were Presbyterians, Lutherans, Baptists, Anglicans, Dutch Reformed, Mennonites and Quakers. While the Church of England was the established church (the official, government-supported church) in the Chesapeake colonies, German and Scottish non-Anglicans were migrating south from the middle colonies, and Baptists were making their first southern converts. Although most Chesapeake slaves were American-born by the late 18th century, they practiced what they remembered of African religions, while some became Christians in 18th-century revivals. [from New Light Schism]
The terms "Old Light" and "New Light" have been applied over the years to several denominational splits, but during the Great Awakening, the debate raged between those who argued that Christianity was more about right doctrine and theology and those who emphasized personal transformation as a result of one's theology. Old Lights were criticized for only caring about one's beliefs, while disregarding behavior such as drunkenness and greed; and New Lights were criticized for their focus on experience and emotion. What began as a split between Presbyterians and Congregationalists birthed the movement called New Light Baptists, when a group of folks influenced by George Whitefield's preaching decided they could find no evidence in Scripture of infant baptism.
Another Baptist of note was Roger Williams, who founded the very first Baptist congregation in the American colonies (1638, Rhode Island). Not until the First Great Awakening, however, did the term "New Light" become associated with Baptists, when many of them broke away from their Calvinist leanings and it was not held as a complimentary term by those of more established denominations.
Woodhouse rails against New Lights as unlearned, unstable, overly emotional, given to fleshly impulse and vice. He bemoans their lack of Scriptural grounding, their quibbling over liturgical service elements while indulging in public indecency, and their exercise of spiritual gifts as a cloak for sinful indulgence. Doesn't sound so different from criticism between churches today, does it? His accounts tell of shenanigans ranging from a sensuality to rival any modern tabloid, to the cultish and downright criminal. Just the reading of it is enough to make one question one's entire upbringing.
It just goes to show that even the most august structures can have less than auspicious beginnings ... and human nature has certainly never changed, when left to itself.
Despite all that, the Baptist church as a whole found a home in the Carolinas, put down roots, spread across the colonies and into the frontier, becoming a solid, established expression of early American faith alongside more settled and staid denominations.
New Lights (from NCpedia)
Old and New Light (from Wikipedia)
Baptists (from Wikipedia)