Colonial dating in 1776 radiometric dating on sedimentary rocks
These have been collected in an atlas by Marshall & Peckham and several show areas of Pennsylvania covering British General Sir William Howe's invasion of the state and seizure of Philadelphia in 1777.
William Faden engraved and published a number of Revolutionary War maps shortly after the events depicted on them occurred.
Bedford County with the county seat at (Fort) Bedford was created in 1771.
Northumberland County with the seat at Sunbury was created in 1772, followed by Westmoreland County in 1773 with the seat at Hannastown, later moved to Greensburg. Philadelphia, Printed by James Nevil, for the author, April 4st, 1770.
The title appears on the upper part: PARTIE DE L'AMERIQUE SEPTENTRIONALE, QUE COMPREND LE CANADA, LA LOUISIANE, LE LABRADOR, LE GROENLAND, LA NOUVELLE ANGLETERRE, LA FLORIDE &C. A MAP OF PART OF PENNSYLVANIA & MARYLAND INTENDED TO SHEW, AT ONE VIEW, THE SEVERAL PLACES PROPOSED FOR OPENING A COMMUNICATION BETWEEN THE WATERS OF THE DELAWARE & CHESOPEAK BAYS.
The southern boundary was fixed by the 1768 Mason-Dixon survey only as far as the Maryland boundary extends.But only the northern states are shown on it and 'Etats Unis' is not actually in the title which refers to the thirteen colonies, 'Treize Colonies'.A 1778 reissue of a previous de Vaugondy map, CARTE DU CANADA ET DES ETATS-UNIS DE L'AMERIQUE SEPTENTRIONALE..., has Etats-Unis in the title and would seem to have a better claim. Com , Issue 1, where a list of United States maps published between 17 is given and this topic is discussed; also see chapter 4 in Ristow.The United States of America was created in this decade.Like the French & Indian War, the Revolutionary War resulted in a number of manuscript maps of marches and battles from 1776 on.