The undersigned, Secretary of State of the United States, has the honor to acknowledge the receipt of the note which Mr. Vaughan, His Britannic Majesty's envoy extraordinary and minister plenipotentiary, addressed to him on the 10th of April, stating upon the authority of a letter from the governor of New Brunswick, whereof a copy came inclosed in Mr. Vaughan's note, that it was apparently the intention of the Government of the United States to carry the road now making through the State of Maine to Mars Hill over that point, and to occupy Mars Hill as a military station; and protesting against such occupation upon the ground that the line drawn by the commissioners of boundary under the treaty of Ghent due north from the monument which marks the source of the river St. Croix was not considered by them as correctly laid down, and that it yet remains to be determined whether Mars Hill is eastward or westward of the true line. The undersigned deems it unnecessary upon the present occasion to enter into an elaborate discussion of the point stated by Sir Howard Douglas, the lieutenant-governor of New Brunswick, concerning the line referred to by him, inasmuch as the relative position of Mars Hill to that line is already designated upon map A, and the line itself mutually agreed to and sufficiently understood for all present purposes, though not definitively settled by the convention of Condon of the 29th September, 1827. The undersigned will therefore merely state that he finds nothing in the record of the proceedings of the commissioners under the fifth article of the treaty of Ghent to warrant the doubt suggested by the lieutenant-governor of New Brunswick whether Mars Hill lies to the westward of the line to be drawn due north from the monument at the source of the St. Croix to the highlands which divide the waters that empty into the river St. Lawrence from those which empty into the Atlantic Ocean; that the joint surveys and explorations made under that commission place the hill about a mile due west of that line; and that the agent of His Britannic Majesty before the commissioners, so far from intimating any doubt on the point, made it one ground of argument that the true line, when correctly laid down, would necessarily, on account of the ascertained progressive westerly variation of the needle, fall still farther westward.