America had a common language, unlike the European nations, none of which was linguistically homogeneous. in 1789 the majority of Frenchmen did not speak French but were divided by a variety of provincial patois. Englishmen from Yorkshire were incomprehensible to those from Cornwall and vice versa. By contrast, Americans could understand one another from Maine to Georgia. It was very obvious why this should be so, said John Witherspoon, president of Princeton. Since Americans were much more unsettled, and move frequently from place to place, they are not as liable to local peculiarities, either in accent or phraseology.
Witherspoon, John
Philadelphia, PA — Site of the Second Continental Congress and of the signing of the Declaration of Independence; access is available through a Park Ranger tour.
Princeton, NJ — Completed in 1756, it housed the entire “College of New Jersey” for nearly 50 years. During the war, both British and Continental troops quartered there.
Empire of Liberty: A History of the Early Republic, 1789–1815 (2009)