The interesting history of Delaware

I think Delaware is a little strange.  It is really tiny, less than 2,000 square miles with less than 1 million residents.  It used to be a colony called New Sweden, then it was conqured by the Dutch, and then the English (lead by the Duke of York).  The Duke of York then gave it or sold it or leased it (not sure which) to William Penn, the proprietor of Pennsylvania, who desired access to the sea.  At that time it was called the "Lower Counties on the Delaware".  Delaware was then governed jointly with Pennsylvania.

On June 15, 1776, just before the Declaration of Independence was signed, Delaware declared its independence from both Great Britain and Pennsylvania. It apparently separated from Pennsylvania because it wanted to maintain is "peculiar institution".

I have a theory. - Since many of Delaware's leading citizens (eg Bedford, Dickinson) also held property and office in Pennsylvania, and many of Pennsylvania's richest (eg Morris, Willing) got rich importing slaves through Delaware (both before and after Pennsylvania started taxing slave imports, as the PA Gazette and other colonial records confirm), I suspect one reason for separation was the realization by some of the richest citizens in both colonies that the radicals who were gaining the upper hand in the Pennsylvania Assembly would eventually combine with the newly-abolitionist Quakers and other minority sects to make slavery in Pennsylvania illegal. - Which they did, before the Revolution was won. - By separating Delaware, both the "Lower Counties'" slaveowners and those Philadelphians who wished to exploit the "Peculiar Institution" could purchase nearby property where they could keep their field laborers, skilled workers, and women who provided all kinds of domestic services, despite Pennsylvania's increasingly broad abolition law. http://www.answers.com/Q/When_did_delaware_separate_from_pennsylvania

So it is clear that Pennsylvania and Delaware are twins in my chart.  And I guess Maryland is a loner.