Delaware did not exist as a colony under British rule. As of 1704, Pennsylvania had two colonial assemblies: one for the "Upper Counties," originally Bucks, Chester and Philadelphia, and one for the "Lower Counties on the Delaware" of New Castle, Kent and Sussex. All of the counties shared one governor.
Thomas McKean and Caesar Rodney, the same two men who represented the Lower Counties in the Stamp Act Congress of 1765, proposed the Lower Counties' simultaneous separation from Pennsylvania and the British crown. McKean and Rodney, along with George Read, represented the Lower Counties at the First Continental Congress in 1774 as well as the Second Continental Congress in 1775-76. When Read refused to vote for independence, McKean had famously summoned an ailing Rodney, who rode overnight from Dover, Delaware, to Philadelphia in order to cast his vote in favor of independence and break the Delaware delegation's stalemate.
McKean and Rodney were punished for their zealous pursuit of independence in an area heavily populated by Loyalists. The first Delaware General Assembly, a body that owed its existence to McKean and Rodney, chose not to return them to the Continental Congress in October 1776. But, after Wilmington, Delaware, and Philadelphia, Pennsylvania, fell under British occupation, the second General Assembly returned the two Patriots to the Continental Congress in October 1777. Both men went on to serve as president of the state of Delaware. Rodney held the post from March 31, 1778, to November 6, 1781. McKean served briefly as the acting president from September 22 until October 20, 1777, while George Read traveled from Philadelphia to assume the post, left vacant by John McKinly's capture by British troops.