Persevering efforts have been made for the adjustment of the claims of American citizens against the Government of Costa Rica, and I am happy to inform you that these have finally prevailed. A convention was signed at the city of San Jose on the 2d July last, between the minister resident of the United States in Costa Rica and the plenipotentiaries of that Republic, referring these claims to a board of commissioners and providing for the payment of their awards. This convention will be submitted immediately to the Senate for their constitutional action.

The claims of our citizens upon the Republic of Nicaragua have not yet been provided for by treaty, although diligent efforts for this purpose have been made by our minister resident to that Republic. These are still continued, with a fair prospect of success.

Our relations with Mexico remain in a most unsatisfactory condition. In my last two annual messages I discussed extensively the subject of these relations, and do not now propose to repeat at length the facts and arguments then presented. They proved conclusively that our citizens residing in Mexico and our merchants trading thereto had suffered a series of wrongs and outrages such as we have never patiently borne from any other nation. For these our successive ministers, invoking the faith of treaties, had in the name of their country persistently demanded redress and indemnification, but without the slightest effect. Indeed, so confident had the Mexican authorities become of our patient endurance that they universally believed they might commit these outrages upon American citizens with absolute impunity. Thus wrote our minister in 1856, and expressed the opinion that “nothing but a manifestation of the power of the Government and of its purpose to punish these wrongs will avail.”

Afterwards, in 1857, came the adoption of a new constitution for Mexico, the election of a President and Congress under its provisions, and the inauguration of the President. Within one short month, however, this President was expelled from the capital by a rebellion in the army, and the supreme power of the Republic was assigned to General Zuloaga. This usurper was in his turn soon compelled to retire and give place to General Miramon.

Under the constitution which had thus been adopted Senor Juarez, as chief justice of the supreme court, became the lawful President of the Republic, and it was for the maintenance of the constitution and his authority derived from it that the civil war commenced and still continues to be prosecuted.

Throughout the year 1858 the constitutional party grew stronger and stronger. In the previous history of Mexico a successful military revolution at the capital had almost universally been the signal for submission throughout the Republic. Not so on the present occasion. A majority of the citizens persistently sustained the constitutional Government. When this was recognized, in April, 1859, by the Government of the United States, its authority extended over a large majority of the Mexican States and people, including Vera Cruz and all the other important seaports of the Republic. From that period our commerce with Mexico began to revive, and the constitutional Government has afforded it all the protection in its power.

Meanwhile the Government of Miramon still held sway at the capital and over the surrounding country, and continued its outrages against the few American citizens who still had the courage to remain within its power. To cap the climax, after the battle of Tacubaya, in April, 1859, General Marquez ordered three citizens of the United States, two of them physicians, to be seized in the hospital at that place, taken out and shot, without crime and without trial. This was done, notwithstanding our unfortunate countrymen were at the moment engaged in the holy cause of affording relief to the soldiers of both parties who had been wounded in the battle, without making any distinction between them.

The time had arrived, in my opinion, when this Government was bound to exert its power to avenge and redress the wrongs of our citizens and to afford them protection in Mexico. The interposing obstacle was that the portion of the country under the sway of Miramon could not be reached without passing over territory under the jurisdiction of the constitutional Government. Under these circumstances I deemed it my duty to recommend to Congress in my last annual message the employment of a sufficient military force to penetrate into the interior, where the Government of Miramon was to be found, with or, if need be, without the consent of the Juarez Government, though it was not doubted that this consent could be obtained. Never have I had a clearer conviction on any subject than of the justice as well as wisdom of such a policy. No other alternative was left except the entire abandonment of our fellow-citizens who had gone to Mexico under the faith of treaties to the systematic injustice, cruelty, and oppression of Miramon’s Government. Besides, it is almost certain that the simple authority to employ this force would of itself have accomplished all our objects without striking a single blow. The constitutional Government would then ere this have been established at the City of Mexico, and would have been ready and willing to the extent of its ability to do us justice.

In addition--and I deem this a most important consideration--European Governments would have been deprived of all pretext to interfere in the territorial and domestic concerns of Mexico. We should thus have been relieved from the obligation of resisting, even by force should this become necessary, any attempt by these Governments to deprive our neighboring Republic of portions of her territory--a duty from which we could not shrink without abandoning the traditional and established policy of the American people. I am happy to observe that, firmly relying upon the justice and good faith of these Governments, there is no present danger that such a contingency will happen.

Having discovered that my recommendations would not be sustained by Congress, the next alternative was to accomplish in some degree, if possible, the same objects by treaty stipulations with the constitutional Government. Such treaties were accordingly concluded by our late able and excellent minister to Mexico, and on the 4th of January last were submitted to the Senate for ratification. As these have not yet received the final action of that body, it would be improper for me to present a detailed statement of their provisions. Still, I may be permitted to express the opinion in advance that they are calculated to promote the agricultural, manufacturing, and commercial interests of the country and to secure our just influence with an adjoining Republic as to whose fortunes and fate we can never feel indifferent, whilst at the same time they provide for the payment of a considerable amount toward the satisfaction of the claims of our injured fellow-citizens.