The Kirk, the informal name of the National Presbyterian “Church of Scotland”, was the only dissenting religious group that simultaneously valued a "republican" style of church government, an inbred hostility to English monarchs, and independent mindedness. In its first 100 years they helped the overthrow of one monarch (Mary, Queen of Scots) and the regicide of another (Charles I). It even forced the faux conversion of Charles II to the Solemn League and Covenant before he had enough popular support to throw off, what was to him, a very distasteful medicine.
The Presbyterians who made many of the greatest contributions to the revolutionary thought and opinion of the masses were mostly from that war torn Northern tip of Ireland. They were a people who were justly and righteously attached to their freedom. The church government lent itself favorably to this value. One of the main points of contention between the Scottish Kirk and Anglican worship was the Bishop oriented rule of the Church of England. The Scots held that every principle of the reformation taught that religious power was to be decentralized in order to be purified of what they felt was the Catholic propensity to abuse it. Congregations chose their minister rather than having one assigned. This was a very strong factor in allowing the American mind to contemplate self government in the political sphere.
These Scots-Irish immigrants to the New World experienced even more autonomy than the rest of colonial America. This was due to the fact that they had been relegated to the back country at the foothills and deeper into the Appalachian Mountains. Their exile was because their Anglican neighbors in the flatlands nearer the coast made this bargain: They would not impose Anglican form of worship on these folks if they would confine themselves to the back country, act as a buffer between the coastal population and the Native Americans, and not “pollute” the Anglican religion with their Presbyterian theology. These rugged individualists felt no compunction in taking this deal. They knew first hand the hard work of establishing themselves in hostile territory. They also relished the freedom they were being given to determine their own destiny.
This thirst for freedom along with a self sacrificing bent to preserve it added immeasurably to the willingness of the American public to revolt. Their traditionally more republican form of church government also prepared them to accept the representative form of government that the American Revolution promised. Even King George acknowledged this influence when he called the rebellion a "Presbyterian War". Many great Scottish born Presbyterian leaders were even to be signers of the Declaration of Independence. One of the most notable was the Rev. John Witherspoon who was also the President of what is now called Princeton University!
Born Fighting: How the Scots-Irish Shaped America by James Webb, 2004, Random House
A Religious History of the American People by Sydney E. Ahlstrom, 2004, Yale University Press
Albion’s Seed, Four British Folkways in America by David Hackett Fischer, 1989, Oxford University Press
Scots in the USA by Jenny Calder, 2006, Luath Press