Connected with the settlement of the line of the northeastern boundary, so far as it respects the States of Maine and Massachusetts, is the continuation of that line along the highlands to the northwesternmost head of Connecticut River.  Which of the sources of that stream is entitled to this character has been matter of controversy and of some interest to the State of New Hampshire.  The King of the Netherlands decided the main branch to be the northwesternmost head of the Connecticut.  This did not satisfy the claim of New Hampshire.  The line agreed to in the present treaty follows the highlands to the head of Halls Stream and thence down that river, embracing the whole claim of New Hampshire and establishing her title to 100,000 acres of territory more than she would have had by the decision of the King of the Netherlands.

By the treaty of 1783 the line is to proceed down the Connecticut River to the forty-fifth degree of north latitude, and thence west by that parallel till it strikes the St. Lawrence.  Recent examinations having ascertained that the line heretofore received as the true line of latitude between those points was erroneous, and that the correction of this error would not only leave on the British side a considerable tract of territory heretofore supposed to belong to the States of Vermont and New York, but also Rouses Point, the site of a military work of the United States, it has been regarded as an object of importance not only to establish the rights and jurisdiction of those States up to the line to which they have been considered to extend, but also to comprehend Rouses Point within the territory of the United States.  The relinquishment by the British Government of all the territory south of the line heretofore considered to be the true line has been obtained, and the consideration for this relinquishment is to inure by the provisions of the treaty to the States of Maine and Massachusetts.

The line of boundary, then, from the source of the St. Croix to the St. Lawrence, so far as Maine and Massachusetts are concerned, is fixed by their own consent and for considerations satisfactory to them, the chief of these considerations being the privilege of transporting the lumber and agricultural products grown and raised in Maine on the waters of the St. Johns and its tributaries down that river to the ocean free from imposition or disability.  The importance of this privilege, perpetual in its terms, to a country covered at present by pine forests of great value, and much of it capable hereafter of agricultural improvement, is not a matter upon which the opinion of intelligent men is likely to be divided.

So far as New Hampshire is concerned, the treaty secures all that she requires, and New York and Vermont are quieted to the extent of their claim and occupation.  The difference which would be made in the northern boundary of these two States by correcting the parallel of latitude may be seen on Tanner’s maps (1836), new atlas, maps Nos. 6 and 9.