It is impossible to leave out of the reckoning, in telling the story of the canal, the checkered history of the diplomatic engagements on the part of the United States, that have served both to help and to hinder the undertaking. What is now the Republic of Panama has been, for the greater part of the time since continental Latin America threw off the yoke of Spain, a part of that Republic having its capital at Bogota, now under the name of Colombia, sometimes under the name of New Granada, sometimes a part of a federation including Venezuela and Ecuador. The United States, by virtue of the Monroe doctrine, always asserted a vague and undefined interest in the local affairs of the Isthmus. This was translated into a concrete interest when, in 1846, a treaty was made, covering the construction of the railroad across the Isthmus, the United States engaging always to keep the transit free and open. Great Britain, by virtue of small territorial holdings in Central America and of larger claims there, also had a concrete interest, which was acknowledged by the United States, in the Clayton-Bulwer treaty of 1850, under which a projected canal should be neutral under the guarantee of the Governments of the United States and Great Britain. For years the United States was inclined to favor a canal cut through Nicaragua, rather than one at Panama, and, after 1898, when the American nation had made up its mind to build a canal somewhere, the partisans of the Panama and Nicaragua routes waged a bitter controversy. Congress finally decided the issue by giving the President authority to construct a canal at Panama, with the proviso that should he be unable to negotiate a satisfactory treaty with Colombia, which then owned the Isthmus, he should proceed to construct the canal through Nicaragua. Under this threat of having the scepter of commercial power depart forever from Panama, Colombia negotiated a treaty, known as the Hay-Herran treaty, giving the United States the right to construct the canal. This treaty, however, failed of ratification by the Colombian Congress, with the connivance of the very Colombian President who had negotiated it. But President Roosevelt was most unwilling to accept the alternative given him by Congress--that of undertaking the canal at Nicaragua--and this unwillingness, to say the least, encouraged a revolution in Panama. This revolution separated the Isthmus from the Republic of Colombia, and set up the new Republic of Panama. As a matter of fact, Panama had had but the slenderest relations with the Bogota Government, had been for years in the past an independent State, had never ceased to assert its own sovereignty, and had been, indeed, the theater of innumerable revolutions.