Thomas Jefferson Papers

Memoranda on the Virginia, Pennsylvania, and Maryland Boundaries, [5 November 1776]

Memoranda on the Virginia, Pennsylvania, and Maryland Boundaries

[5 November 1776]

If the Monongahela is the line it will throw 300. Virginia families into Pennsylva. Most of these live between the Yohiogany and Monongahela. Not one third of that number of Pennsylvanians would be thrown on the Virginia side.

If the Laurel hill is the boundary it will place on the Virginia side all the Virginia settlers, and about 200. families of Pennsylvania settlers.

A middle line is thought to be just.

Braddock’s old road crosses the Yohiogany in the Allegany mountain. Then turns along by the head of Redstone on the West side the Yohiogany and crosses the Laurel hill about 6. miles from Stewart’s (or Hart’s) crossing, then crosses the river at Stewart’s crossing, Jacob’s creek 4. mi. above mouth, Swiglie 5. mi. above mouth, then goes down to the Monongahela about 2 mi. below the mouth of Yohiagany then recrosses it within a mile, and there stopped. A line then run from the mouth of Turtle creek to the mouth of the first creek that empties into the Allegany above Croghan’s. This would give tolerable satisfaction to Virginia, would throw about 150 Pennsylvas. into Virga. and about 20. or 30 Virginians into Pennsylva. The 150. Pennsylvas. live in such manner dispersed on the Yohiogany and Monongahela that no line will throw them into Pennsylva.

If Braddock’s road cannot be established, the Laurel hill and Yohiogany might do without great uneasiness, and so from mouth of Turtle as before.


‘All that tract or part of land in America, with the islands therein contained, as the same is bounded on the East by Delaware river, from twelve miles distance Northwards of Newcastle town unto the three and fortieth degree of Northern latitude, if the said river doth extend so far Northward; but if the said river shall not extend so far Northward, then by the said river so far as it doth extend; and from the head of the said river, the Eastern bounds are to be determined by a Meridian line, to be drawn from the head of the said river unto the said forty third degree. The said land to extend Westward five degrees in Longitude, to be computed from the said Eastern bounds; and the said lands to be bounded on the North by the beginning of the three and fortieth degree of Northern latitude, and on the South by a circle drawn at twelve miles distance from Newcastle Northward and Westward unto the beginning of the fortieth degree of Northern Latitude, and then by a straight line Westwards to the limits of longitude, abovementioned.’

Most Southern point of Philadelphia is in Longitude from Greenwich 5H–0′–35″ West. Latitude 39°–56′–29″,2

The length of a degree of latitude as measured by Mason and Dixon is 68.896 statute miles.

The boundary between Maryland and Pennsylvania was agreed by Ld. Baltimore and Penn to be a line of Latitude 15. miles South of Philadelphia, from the intersection of that line with the Meridian tangent of the circle drawn round Newcastle by a 12 miles radius.

This process therefore will determine the latitude of that line.

Miles Miles

As 68.899 :: 1° :: 15 : 13′–3″. 7 difference between
  Latitude of Philadelphia and the boundary line.
Therefore from 39°–56′–29″.2 the Latitude of Philadelphia
  Deduct     13– 3 .7 the difference of Latitude
  leaves 39°–43′–25″.5 the latitude of the line.
Therefore Pennsylvania is to run down 43′–25″.5 Southwardly.


Maryland charter dated 8. Car. 1. June 20.

to Cecilius Calvert Baron of Baltimore in Ireland. ‘All that part of a peninsula lying in the parts of America between the ocean on the east and the bay of Chesepeak on the West and divided from the other part thereof by a right line drawn from the promontory or cape of land called Watkins point (situate in the aforesaid bay near the river Wigheo) on the west unto the main ocean on the East, and between that bound on the South unto the part of delaware bay on the North which lieth under the fortieth degree of Northerly latitude from the Equinoctial where New-England ends: and all the tract of land between the bounds aforesaid, that is to say, passing from the aforesaid bay called Delaware bay in a right line by the degree aforesaid unto the true meridian of the first fountain of the river Puttowmack, and from thence tending toward the South unto the further bank of the aforesaid river and following the West and South side thereof unto a certain place called Cinquack, situate near the mouth of the said river where it falls into the bay of Cheseapeack and from thence by a streight line unto the aforesaid promontory and place called Watkin’s point (so that all that tract of land divided by the line aforesaid drawn between the main ocean and Watkin’s point unto the promontory called cape Charles and all it’s appurtenances do remain entirely excepted to us our heirs and successors for ever.)’

The above is extracted from a book of Col. Byrd’s bound in Vellum lettered ‘Antient Records’ which contains most of the colony charters, together with copies of public papers of various kinds which seem to be extracted principally from the Records, they come down as low as Apr. 28. 1722.


1663. c. 2. Pervis: an act concerning the bounds of this Collonie on the Easterne shoare.


Common acceptation of location of degree. Maryland charter proves it. Qu. 1. Vezey. 444.

It is nearer to end of 40°.

Mistake in latitude

End of 39°. strikes ocean, not Delaware.

Penn gave Baltimore £5000 to run the line where it is. This is the compromise enforced in Vezey. Why not confine him to begin somewhere in the circle, which is one of the specific parts of description.


The grant of the Northern neck 1. Car. 2. being 32 years before the grant of Pennsylva. to Penn effectually excludes so much of their Southern claim as comes within Ld. Fairfax’s territory.

N (DLC). This is a collection of notes written on three sheets of paper of different dimensions and with different watermarks.

These memoranda were set down at several different times, doubtless over a period of years, for the handwriting and ink vary markedly from one group of notes to another, and sometimes from one part of the same sheet of paper to another part. The several sections are here indicated by rules between them, but attempts to date the different sections have proved inconclusive. They are printed all together because they are so gathered in Jefferson’s papers, and under this date because on 5 Nov. 1776 TJ was named at the head of a committee of the House of Delegates to make a fresh proposal for a permanent line between Virginia and Pennsylvania (JHD description begins Journal of the House of Delegates of the Commonwealth of Virginia (cited by session and date of publication) description ends , Oct. 1776, 1828 edn., p. 41; see letter of Virginia Delegates to Pennsylvania Convention, 15 July 1776). The committee did not report until 17 Dec., three days after TJ had left Williamsburg; it is therefore impossible to determine TJ’s share in the new proposal. Brought in by George Mason and adopted by the House, the report yielded the Forks of the Ohio to Pennsylvania, following precisely the western (but not the southern) line claimed by Gov. Penn in 1774 (JHD description begins Journal of the House of Delegates of the Commonwealth of Virginia (cited by session and date of publication) description ends , Oct. 1776, 1828 edn., p. 101; Paullin and Wright, Atlas, pl. 97G). The dispute by no means ended here, but during the national struggle of the next two years it was quiescent, and TJ was not concerned with it again until he became governor. Pervis: John Purvis, comp., A Complete Collection of All the Laws of Virginia Now in Force, London [1684?]. Vezey: Francis Vesey, the elder, comp., Cases Argued and Determined in … Chancery, … from … 1746–7 to 1755, London, 1771. Both these works were owned by TJ (Library Catalogue, 1815 description begins Catalogue of the Library of the United States, Washington, 1815 description ends , p. 73, 72).

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