By uniting we stand, by dividing we fall."
This is the quotation most often mentioned when I google John Dickinson quotes. I have a feeling it was script writing, and not a true quote.
Here's an interesting paragraph from an article on the internet:
"Historians have labeled John Dickinson cautious and conservative. Cautious he was, in part too bound by his great dependence on lessons gained from both English and world history. To certain aspects of history he seemed blind, perhaps as a result of a temperamental revulsion to mass violence. His caution alone caused him to called conservative. But his devotion to the rule of law and to the principles of liberty linked him to the radicals in the early days of the Revolution. Dickinson never changed his principles. A man of great moral courage, he refused to bow to popular clamor and support independence. A conservative stance which seeks to withstand the ongoing currents of a dynamic world cannot, inherently, be a popular one. It tends to obstruct and frustrate. Thus the defender earns calumny from the impatient. Such was the case with Dickinson in Pennsylvania at the time of independence, a fate reversed, however, once his moderation again proved desirable. His life thus is not that of the more familiar Founding Fathers, but of a man no less devoted to his country and important in its history."
http://odur.let.rug.nl/~usa/B/jdickenson/johnd1.htm