In The American Revolution, 1763-1783, William Lecky notes that the Revolution wasn’t completely unpredictable:
Several acute observers had already predicted that the triumph of England [over France] would be soon followed by the revolt of her colonies. I have quoted in a former chapter the remarkable passage in which the Swedish traveller, Kalm, contended in 1748 that the presence of the French in Canada, by making the English colonists depend for their security on the support of the mother country, was the main cause of the submission of the colonies.
In his ‘Notes upon England,’ which were probably written about 1730, Montesquieu had dilated upon the restrictive character of the English commercial code, and had expressed his belief that England would be the first nation abandoned by her colonies.
A few years later, Argenson, who has left some of the most striking political predictions upon record, foretold in his Memoirs that the English colonies in America would one day rise against the mother country, that they would form themselves into a republic, and that they would astonish the world by their prosperity.
In a discourse delivered before the Sorbonne in 1750 Turgot compared colonies to fruits which only remain on the stem till they have reached the period of maturity, and he prophesied that America would some day detach herself from the parent tree.
The French ministers consoled themselves for the Peace of Paris by the reflection that the loss of Canada was a sure prelude to the independence of the colonies; and Vergennes, the sagacious’ French ambassador at Constantinople, predicted to an English traveller, with striking accuracy, the events that Would occur. ‘ England,’ he said, ‘will soon repent of having removed the only check that could keep her colonies in awe. They stand no longer in need of her protection. She will call on them to contribute towards supporting the burdens they have helped to bring on her, and they will answer by striking off all dependence.’