The Convention (at Cleveland, 1854), in its Secret Sessions made, Africa, with its rich, inexhaustible productions, and great facilities for checking the abominable Slave Trade, its most important point of dependence, though each individual was left to take the direction which in his judgment best suited him. Though our great gun was leveled, and the first shell thrown at the American Continent, driving a slaveholding faction into despair, and a political confusion from which they have been utterly unable to extricate themselves, but become more and more complicated every year, _Africa was held in reserve, until by the help of an All-wise Providence we could effect what has just been accomplished with signal success_--a work which the most sanguine friend of the cause believed would require at least the half of a century. It is a curious, and not less singular historical fact, that a leading political journal, and the first newspaper which nominated Mr. James Buchanan, many years ago, for the Presidency of the United States; and at a time whilst he was yet at the court of St. James (1854), as Envoy Extraordinary, this paper was strongly urging his claims as such, thus expresses itself, which gives a fair idea of the political pro-slavery press generally, especially in Pennsylvania, Mr. Buchanan's native State. I intended to give the article entire, as alarm will be seen even at the commencement; but pressure for space will prevent my quoting but a few sentences. It is from the Pittsburgh _Daily Morning Post_, Wednesday, October 18th, 1854: A GRAND SCHEME FOR THE COLORED RACE In August last, a National Convention of colored people was held at Cleveland, Ohio. It was composed of delegates from most of the States. It was called the 'National Emigration Convention,' and its objects were to consider the political destinies of the black race; and recommend a plan of Emigration to countries where they can enjoy political liberty, and form nations 'free and independent.'