During the Revolutionary period, the big north-south divide within the future U.S. of A. was not at the relatively recent Mason-Dixon line defining the southern border of Pennsylvania. Rather, it was at the border between New England and New York.
East of that border, the colonies had been settled by Puritans, and were still dominated by the Congregationalist orthodoxy. Only small minorities adhered to the Church of England and Society of Friends, the largest and/or most influential religions in colonies to the south.
Landholdings in New England were relatively small and equal. The climate didn’t allow for the big cash crops of tobacco, indigo, and rice, meaning plantation slavery hadn’t taken hold. New York grants blocked expansion to the west, so the Proclamation of 1763 didn’t matter so much as it did to whites in the southern colonies.
John Adams expressed these differences to Joseph Hawley, the most prominent Patriot politician in western Massachusetts, in a letter dated 25 Nov 1775:
The Characters of Gentlemen in the four New England Colonies, differ as much from those in the others, as that of the Common People differs, that is as much as several distinct Nations almost.I should note that Adams hadn’t actually traveled south of Philadelphia yet. Fortunately for him, this was not one of his letters that fell into British hands that season, or it would probably have cost him even more allies in the Continental Congress.
Gentlemen, Men of Sense, or any Kind of Education in the other Colonies are much fewer in Proportion than in N. England. Gentlemen in the other Colonies have large Plantations of slaves, and the common People among them are very ignorant and very poor. These Gentlemen are accustomed, habituated to higher Notions of themselves and the distinction between them and the common People, than We are. And an instantaneous alteration of the Character of a Colony, and that Temper and those Sentiments which its Inhabitants imbibed with their Mothers Milk, and which have grown with their Growth and strengthened with their Strength, cannot be made without a Miracle.
I dread the Consequences of this Disimilitude of Character, and without the Utmost Caution on both sides, and the most considerate Forbearance with one another and prudent Condescention on both sides, they will certainly be fatal. An Alteration of the Southern Constitutions, which must certainly take Place if this War continues[,] will gradually bring all the Continent nearer and nearer to each other in all Respects. But this is the Most Critical Moment, We have yet seen. This Winter will cast the Die.
The thumbnail above shows a 1775 map of New England and Long Island, available from Colonial Williamsburg.