I tried looking at this subject a couple of years ago but was unable to come up with anything definitive. This looks a lot more like it.

http://www.ecwsa.org/English_Civil_W...n_Colonies.pdf

Whilst clashes between Marylanders and Virginians in the 1630s had
been about local rivalries what made the ‘Battle of Blanck Point’ significant
was not that it was the first armed clash between Englishmen in America but
resulting from events in England rather than in the colonies. Unfortunately,
the significance was not lost on the local Powhatan Indians who witnessed
this clash between English ships. 16 Armed with the knowledge that across
the Atlantic the English were at war with themselves, Pocahontas’ uncle
sachem Opchanacanough launched a pre-emptive strike against the Virginia
colonists on 18 April 1644 killing between 300-400 settlers.
Wow, that is an awful lot of folks for the colonies at that time.