From Wikipedia:
Covenanters were members of a 17th-century Scottish religious and political movement, who supported a Presbyterian Church of Scotland, and the primacy of its leaders in religious affairs. The name derived from Covenant, a biblical term for a bond or agreement with God.
The origins of the movement lay in disputes with James VI & I, and his son Charles I of England over church structure and doctrine. In 1638, thousands of Scots signed the National Covenant, pledging to resist changes imposed by Charles on the kirk; following victory in the 1639 and 1640 Bishops’ Wars, the Covenanters took control of Scotland.
After the 1660 Restoration, the Covenanters lost control of the kirk and became a persecuted minority, leading to several armed rebellions and a period from 1679 to 1688 known as “The Killing Time”. Following the 1688 Glorious Revolution in Scotland, the Church of Scotland was re-established as a wholly Presbyterian structure and most Covenanters readmitted. This marked the end of their existence as a significant movement, although dissident minorities persisted in Scotland, Ireland, and North America.
Throughout the 17th century, Covenanter congregations were established in Ireland, primarily in Ulster; for a variety of reasons, many subsequently migrated to North America. In 1717, William Tennent moved with his family to Philadelphia, where he later founded Log College, the first Presbyterian seminary in North America.
In North America, many former Covenanters joined the Reformed Presbyterian Church of North America, which was founded in 1743. They were among the most vocal agitators for independence from Great Britain and volunteered in large numbers as soldiers in the revolutionary armies; in 1800, the Reformed Church voted to outlaw slave-holding among its members.