were racial and social differences prevalent during the American revolution? differences among each other?

Answer 1

I don't think they had started bringing in the African slaves yet, but the social differences would be religion . . . as most were Puritans and quite domineering.
When did the first slave ships arrive ?

Whoops, my mistake !

Beginning in the 1750s Quaker meetings attempted to persuade their members that they should not own slaves; some who resisted were expelled. Quakers dominated all the abolition societies. There was widespread sentiment during the Revolution that slavery was a social evil (for the country as a whole and for the whites) should eventually be abolished. All the Northern states passed emancipation acts between 1780 and 1804; most of these arranged for gradual emancipation and a special status for freedmen, so there were still a dozen "permanent apprentices" in New Jersey in 1860. [2]

adding
http://en.wikipedia.org/wiki/History_of_slavery_in_the_United_States