SLAVERY AGITATION.

The great object of the Democracy has been, for years past, to put a stop to slavery agitation. - This was not to be done by any physical means, nor by shutting their eyes and closing their ears to the fierce encroachment of fanaticism at the North; but they have endeavored to do so upon great Constitutional principles of equality and fairness - principles on which the good men of all parties could unite. There has been but one thing that has prevented the Democracy from consummating this great end, the want of a cordial co-operation of all parties in the South. But for the distraction produced by Know-Nothingism, we would easily have made a complete crush of it long since. Let the entire South, and all national men of the country, unite cordially with the Democracy on this question, however much they may differ as to others, and we can in a little time rid ourselves of this unceasing agitation, and turn the attention of our public men to more healthy subjects of national interest.

Instead of pursuing this course, it has been the policy of unscrupulous politicians, who desired to figure in the lead of faction, to turn their batteries against the Democracy and keep up the unceasing cry that it was they who were producing all the agitation in the country. They have persisted in this until they have made many honest people of their party seriously believe it.

The recent opinion of the Supreme Court of the United States -- that great tribunal of the country before whose decisions all parties and all factions must give way - fully and completely vindicates and sustains the Democratic party in the patriotism and wisdom of its course throughout the entire history of slavery agitation. From this decision there is no appeal except to revolution. We might well infer, therefore, that the agitation would cease. But not so, if we are to credit the New York Post, a journal of high authority with the Black Republicans. It says:

Some of the journalists who support the cause of the administration are pleasing themselves with the fancy that the decision of the Supreme Court of the United States in the Dred Scott Case will put an end to the agitation of the slavery question. They will soon find their mistake. The feeling in favor of liberty is not so easily smothered; discussion is not so readily silenced. One specific after another has been tried, with the same view and with the same success. The Fugitive Slave Law, we were told, was to quiet all agitation, but it did not; the Nebraska bill was to stop all controversy on the slavery question, but it proved to be oil poured on the flames. The usurpation of the government of Kansas by the inroad from Missouri, was thought for a time to be a blow to the friends of liberty which they could not survive, but it only roused them to greater activity. The election of Mr. Buchanan as President in November was to put an end to the dispute, but since November the dispute has waxed warmer and warmer. It will never end till the cause of liberty [Abolitionism] has finally triumphed. Heap statute upon statute, follow up one act of Executive interference with another, add usurpation to usurpation, and judicial decision to judicial decision, the spirit against which they are levelled is indestructible. As long as the press and speech are free, the warfare will be continued, and every attempt to suppress it, by directing against it any part of the machinery of the government will only cause it to rage more fiercely.

The country is thus informed through this authorised organ of Abolitionism that the efforts of the Democracy to settle the slavery agitation will prove fruitless, and that fanaticism is to wage its war of aggression, reckless of the Supreme Court, the Administration, and every thing else; and yet the Louisville Journal and such papers will continue to prate about the persistent agitation of this question by the Democracy!

It is time that the honest members of the Know-Nothing party of the South had their eyes open. It is time that patriots everywhere were beginning to see that there is no safety for the country, in connection with this question, save in a cordial co-operation with the Democracy. Especially in the South must they awaken to this consciousness, where they have such interests to stimulate them, and such practical manifestations of its truth.