It was with surprise and regret, therefore, that the United States learned a few days after the conclusion of the treaty of Guadalupe Hidalgo, by which the United States became, with the consent of the Mexican Republic, the rightful owners of California, and thus invested with augmented special interest in the political condition of Central America, that a military expedition, under the authority of the British Government, had landed at San Juan del Norte, in the State of Nicaragua, and taken forcible possession of that port, the necessary terminus of any canal or railway across the Isthmus within the territories of Nicaragua. It did not diminish the unwelcomeness to us of this act on the part of Great Britain to find that she assumed to justify it on the ground of an alleged protectorship of a small and obscure band of uncivilized Indians, whose proper name had even become lost to history, who did not constitute a state capable of territorial sovereignty either in fact or of right, and all political interest in whom and in the territory they occupied Great Britain had previously renounced by successive treaties with Spain when Spain was sovereign to the country and subsequently with independent Spanish America. Nevertheless, and injuriously affected as the United States conceived themselves to have been by this act of the British Government and by its occupation about the same time of insular and of continental portions of the territory of the State of Honduras, we remembered the many and powerful ties and mutual interests by which Great Britain and the United States are associated, and we proceeded in earnest good faith and with a sincere desire to do whatever might strengthen the bonds of peace between us to negotiate with Great Britain a convention to assure the perfect neutrality of all interoceanic communications across the Isthmus and, as the indispensable condition of such neutrality, the absolute independence of the States of Central America and their complete sovereignty within the limits of their own territory as well against Great Britain as against the United States. We supposed we had accomplished that object by the convention of April 19, 1850, which would never have been signed nor ratified on the part of the United States but for the conviction that in virtue of its provisions neither Great Britain nor the United States was thereafter to exercise any territorial sovereignty in fact or in name in any part of Central America, however or whensoever acquired, either before or afterwards. The essential object of the convention--the neutralization of the Isthmus--would, of course, become a nullity if either Great Britain or the United States were to continue to hold exclusively islands or mainland of the Isthmus, and more especially if, under any claim of protectorship of Indians, either Government were to remain forever sovereign in fact of the Atlantic shores of the three States of Costa Rica, Nicaragua, and Honduras.