The undersigned, Secretary of State of the United States, acknowledges to have received Mr. Fox's communication of the 13th instant, in reference to the boundary negotiation and the affairs of the disputed territory. The information given in the closing part of it—that a reply to the last proposition of the United States upon the subject of the boundary may be expected in a short time—is highly gratifying to the President, who has, however, given directions to the undersigned, in making this acknowledgment, to accompany it with the expression of his profound regret that Mr. Fox's note is in no other respect satisfactory.

After the arrangements which in the beginning of last year were entered into on the part of the two Governments with regard to the occupation of the disputed territory, the President had indulged the hope that the causes of irritation which had grown out of this branch of the subject could have been removed. Relying on the disposition of Maine to cooperate with the Federal Government in all that could lead to a pacific adjustment of the principal question, the President felt confident that his determination to maintain order and peace on the border would be fully carried out. He looked upon all apprehensions of designs by the people of Maine to take possession of the territory as without adequate foundation, deeming it improbable that on the eve of an amicable adjustment of the question any portion of the American people would without cause and without object jeopard the success of the negotiation and endanger the peace of the country. A troublesome, irritating, and comparatively unimportant, because subordinate, subject being thus disposed of, the President hoped that the parties would be left free at once to discuss and finally adjust the principal question. In this he has been disappointed. While the proceedings of Her Majesty's Government at home have been attended with unlooked-for delays, its attention has been diverted from the great subject in controversy by repeated complaints imputing to a portion of the people of the United States designs to violate the engagements of their Government—designs which have never been entertained, and which Mr. Fox knows would receive no countenance from this Government.

It is to be regretted that at this late hour so much misapprehension still exists on the side of the British Government as to the object and obvious meaning of the existing arrangements respecting the disputed territory. The ill success which appears to have attended the efforts made by the undersigned to convey through Mr. Fox to Her Majesty's Government more correct impressions respecting them calls for a recurrence to the subject, and a brief review of the correspondence which has grown out of it may tend to remove the erroneous views which prevail as to the manner in which the terms of the arrangements referred to have been observed.

As Mr. Fox had no authority to make any agreement respecting the exercise of jurisdiction over the disputed territory, that between him and the undersigned of the 27th of February, 1839. had for its object some provisional arrangement for the restoration and preservation of peace in the territory. To accomplish this object it provided that Her Majesty's officers should not seek to expel by military force the armed party which had been sent by Maine into the district bordering on the Restook River, and that, on the other hand, the government of Maine would voluntarily and without needless delay withdraw beyond the bounds of the disputed territory any armed force then within them. Besides this, the arrangement had other objects—the dispersion of notorious trespassers and the protection of public property from depredation. In case future necessity should arise for this, the operation was to be conducted by concert, jointly or separately, according to agreement between the governments of Maine and New Brunswick.

In this last-mentioned respect the agreement looked to some further arrangement between Maine and New Brunswick. Through the agency of General Scott one was agreed to on the 23d and 25th of March following, by which Sir John Harvey bound himself not to seek, without renewed instructions to that effect from his Government, to take military possession of the territory or to expel from it by military force the armed civil posse or the troops of Maine. On the part of Maine it was agreed by her governor that no attempt should be made, without renewed instructions from the legislature, to disturb by arms the Province of New Brunswick in the possession of the Madawaska settlements or interrupt the usual communications between that and the upper Provinces. As to possession and jurisdiction, they were to remain unchanged—each party holding, in fact, possession of part of the disputed territory, but each denying the right of the other to do so. With that understanding Maine was without unnecessary delay to withdraw her military force, leaving only, under a land agent, a small civil posse, armed or unarmed, to protect the timber recently cut and to prevent further depredations.

In the complaints of infractions of the agreements by the State of Maine addressed to the undersigned Mr. Fox has assumed two positions which are not authorized by the terms of those agreements: First. Admitting the right of Maine to maintain a civil posse in the disputed territory for the purposes stated in the agreement, he does so with the restriction that the action of the posse was to be confined within certain limits; and, second, by making the advance of the Maine posse into the valley of the Upper St. John the ground of his complaint of encroachment upon the Madawaska settlement, he assumes to extend the limits of that settlement beyond those it occupied at the date of the agreement.

The United States can not acquiesce in either of these positions.

In the first place, nothing is found in the agreement subscribed to by Governor Fairfield and Sir John Harvey defining any limits in the disputed territory within which the operations of the civil posse of Maine were to be circumscribed. The task of preserving the timber recently cut and of preventing further depredations within the disputed territory was assigned to the State of Maine after her military force should have been withdrawn from it, and it was to be accomplished by a civil posse, armed or unarmed, which was to continue in the territory and to operate in every part of it where its agency might be required to protect the timber already cut and prevent further depredations, without any limitation whatever or any restrictions except such as might be construed into an attempt to disturb by arms the Province of New Brunswick in her possession of the Madawaska settlement or interrupt the usual communication between the Provinces.

It is thus, in the exercise of a legitimate right and in the conscientious discharge of an obligation imposed upon her by a solemn compact, that the State of Maine has done those acts which have given rise to complaints for which no adequate cause is perceived. The undersigned feels confident that when those acts shall have been considered by Her Majesty's Government at home as explained in his note to Mr. Fox of the 24th of December last and in connection with the foregoing remarks they will no longer be viewed as calculated to excite the apprehensions of Her Majesty's Government that the faith of existing arrangements is to be broken on the part of the United States.

With regard to the second position assumed by Mr. Fox—that the advance of the Maine posse along the valley of the Restook to the mouth of Fish River and into the valley of the Upper St. John is at variance with the terms and spirit of the agreements—the undersigned must observe that if at variance with any of their provisions it could only be with those which secure Her Majesty's Province of New Brunswick against any attempt to disturb the possession of the Madawaska settlements and to interrupt the usual communications between New Brunswick and the upper Provinces. The agreement could only have reference to the Madawaska settlements as confined within their actual limits at the time it was subscribed. The undersigned in his note of the 24th of December last stated the reasons why the mouth of Fish River and the portion of the valley of the St. John through which it passes could in no proper sense be considered as embraced in the Madawaska settlements. Were the United States to admit the pretension set up on the part of Great Britain to give to the Madawaska settlements a degree of constructive extension that might at this time suit the purposes of Her Majesty's colonial authorities, those settlements might soon be made with like justice to embrace any portions of the disputed territory, and the right given to the Province of New Brunswick to occupy them temporarily and for a special purpose might by inference quite as plausible give the jurisdiction exercised by Her Majesty's authorities an extent which would render the present state of the question, so long as it could be maintained, equivalent to a decision on the merits of the whole controversy in favor of Great Britain. If the small settlement at Madawaska on the north side of the St. John means the whole valley of that river, if a boom across the Fish River and a station of a small posse on the south side of the St. John at the mouth of Fish River is a disturbance of that settlement, which is 25 miles below, within the meaning of the agreement, it is difficult to conceive that there are any limitations to the pretensions of Her Majesty's Government under it or how the State of Maine could exercise the preventive power with regard to trespassers, which was on her part the great object of the temporary arrangement. The movements of British troops lately witnessed in the disputed territory and the erection of military works for their protection and accommodation, of which authentic information recently received at the Department of State has been communicated to Mr. Fox, impart a still graver aspect to the matter immediately under consideration. The fact of those military operations, established beyond a doubt, left unexplained or unsatisfactorily accounted for by Mr. Fox's note of the 7th instant, continues an abiding cause of complaint on the part of the United States against Her Majesty's colonial agents as inconsistent with arrangements whose main object was to divest a question already sufficiently perplexed and complicated from such embarrassments as those with which the proceedings of the British authorities can not fail to surround it.