The undersigned begs leave to remind Mr. Van Buren that Mars Hill is situated upon the northeastern line of boundary which is in dispute between the two Governments; and he is called upon to protest against the occupation of it by American troops 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 sources of the river St. Croix was not considered by them as correctly laid down, and it yet remains to be determined whether Mars Hill lies eastward or westward of a line drawn upon scientific principles. For a better explanation of the motives for this protest the undersigned has the honor to refer the Secretary of State to a copy of a letter, which is inclosed,[14] from Sir Howard Douglas. A joint resolution of both Houses of Congress passed during the last session tends to confirm the intentions of the Government of the United States as inferred by Sir Howard Douglas from the information which he has received. That resolution authorized the making of a road from and beyond Mars Hill to the mouth of the Madawaska River; but as the carrying into effect that resolution was left entirely to the discretion of the President, the undersigned can not entertain any apprehension of a forcible seizure of a large portion of the disputed territory, which a compliance with the resolution of Congress would imply. The undersigned acknowledges with great satisfaction the assurances which he has received of the kind feelings which will actuate the President of the United States in the adjustment of any differences which may exist with Great Britain. He submits, therefore, the representation of the lieutenant-governor of New Brunswick respecting the occupation of Mars Hill, relying confidently on the manifest propriety of restraining the aggression which it is supposed is meditated from the frontier of the State of Maine, and of both parties mutually abstaining from any acts which can affect the disputed territory, as the question of possession is now in the course of arbitration. The undersigned reiterates to the Secretary of State the assurances of his highest consideration. CHAS. R. VAUGHAN. [Footnote 14: Omitted.] _Mr. Van Buren to Mr. Vaughan_. DEPARTMENT OF STATE, _Washington, May 11, 1829_. Right Hon. CHARGES R. VAUGHAN, etc.: