Convenient means of transit between the several parts of a country are not only desirable for the objects of commercial and personal communication, but essential to its existence under one government. Separated, as are the Atlantic and Pacific coasts of the United States, by the whole breadth of the continent, still the inhabitants of each are closely bound together by community of origin and institutions and by strong attachment to the Union. Hence the constant and increasing intercourse and vast interchange of commercial productions between these remote divisions of the Republic. At the present time the most practicable and only, commodious routes for communication between them are by the way of the isthmus of Central America. It is the duty of the Government to secure these avenues against all danger of interruption. In relation to Central America, perplexing questions existed between the United States and Great Britain at the time of the cession of California. These, as well as questions which subsequently arose concerning interoceanic communication across the Isthmus, were, as it was supposed, adjusted by the treaty of April 19, 1850, but, unfortunately, they have been reopened by serious misunderstanding as to the import of some or its provisions, a readjustment of which is now under consideration. Our minister at London has made strenuous efforts to accomplish this desirable object, but has not yet found it possible to bring the negotiations to a termination. As incidental to these questions, I deem it proper to notice an occurrence which happened in Central America near the close of the last session of Congress. So soon as the necessity was perceived of establishing interoceanic communications across the Isthmus a company was organized, under the authority of the State of Nicaragua, but composed for the most part of citizens of the United States, for the purpose of opening such a transit way by the river San Juan and Lake Nicaragua, which soon became an eligible and much used route in the transportation of our citizens and their property between the Atlantic and Pacific. Meanwhile, and in anticipation of the completion and importance of this transit way, a number of adventurers had taken possession of the old Spanish port at the mouth of the river San Juan in open defiance of the State or States of Central America, which upon their becoming independent had rightfully succeeded to the local sovereignty and jurisdiction of Spain. These adventurers undertook to change the name of the place from San Juan del Norte to Greytown, and though at first pretending to act as the subjects of the fictitious sovereign of the Mosquito Indians, they subsequently repudiated the control of any power whatever, assumed to adopt a distinct political organization, and declared themselves an independent sovereign state. If at some time a faint hope was entertained that they might become a stable and respectable community, that hope soon vanished.