To-day will be an eventful day in the history of this nation. To-day the Convention of South Carolina will meet, a Convention assembled but for one single purpose—that of declaring South Carolina no longer one of the States of the Union. That such will be her action sometime during the present week, we are not permitted to entertain a shadow of doubt.Thus, then, one of the pillars which sustains the national edifice is about to be removed, to be quickly followed by others. South Carolina only precedes, by a few weeks, five or six of her former sisters in the Confederacy. What South Carolina does to-day will be done, very soon, by every one of the Gulf States, and eventually, in all probability, by every Southern State.

What makes the circumstance more significant is the fact that the State which to-day makes her preparations to leave the Union is one of the original thirteen. She was one of those which helped to form the Union, when the Union was first devised. Naturally, she would be regarded as more attached to it than a State subsequently admitted. She does not leave the Union now because she is any the less attached to the Union which our fathers made than she was in the beginning. It is because the present Union is not the Union that our fathers made. It is because the Union has been perverted from its original purposes—because it has become an engine of oppression, instead of a dispenser of blessings—because it is a Union of force instead of one of friendship and love. It is for this that South Carolina determines to seek that safety and security and peace outside of the Union, which she has vainly attempted to obtain within it. It is appropriate, then, that the first State to leave should be one which was an original party to the compact—that the lead of her Southern sisters should be taken by a Commonwealth which was also one of the leaders in the formation of the original Union.

From thirteen States, comparatively small in population and weak in resources, we have grown in less than a century to be a nation of thirty-three States, extending from the Lakes of the North to the Southern Gulf, and from one ocean to the other, across the whole North American Continent. We have become a great nation; and we had the prospect, under a peaceful and just Government, of becoming one of the greatest, if not the very greatest, upon the face of the globe. That these prospects should have to be given up is something which no patriotic American can think of without a feeling of sadness and sorrow—but that they will be given up, firmly and unflinchingly, there remains not a vestige of doubt. The Southern people, driven to the wall, have no remedy but that of political independence. Forbearance has not only ceased to be a virtue, but has become absolute cowardice. And that forbearance has even been interpreted as cowardice by the very people for whose sake we have so long forborne.

The nation, indeed, may have grown too fast. It may have become, too suddenly, one of the great powers of the earth. In the physical world, that which soonest reaches maturity soonest decays. Our free institutions, our broad and smiling land, our great natural advantages, have made a mighty nation of us too soon, perhaps. Less than a century is a short life, even for a Republic. But the causes that underlie the destruction of all Governments—the discontent, and the reluctant obedience and loyalty of large masses of the people—have been operating among us for many years. From the time that the central Government of all the States began to usurp powers not delegated to it in the common bond of the Constitution—legislating for the benefit of classes and sections, and the consequent oppression and injury of the rest—taking upon itself the supervision of the respective States as to their domestic institutions—claiming all powers that the most latitudinous construction of the Constitution could suggest—from this time the seeds of dissolution and decay were planted. And their first fruits we shall to-day see in a State which was one of the battle-fields of the Revolution, and which is as determined now to resist tyranny at home as she was to repel the tyranny which came across the ocean when we were colonies of Great Britain. The sort of liberty which South Carolina wants, she helped to wrest from the mother country, and is equally ready to wrest from the oppressor at home.

The events of this week, then, will satisfy those at the North who have been blind to Southern sentiment how great an error they have made. They thought at first that South Carolina was blustering, and would soon get over her sacred passion. After a while they concluded that South Carolina was in earnest—but that she would be solitary and alone in leaving the Union. Presently they discovered that the same causes which impelled one Southern State to withdraw were operating in all of them. And when popular manifestations, legislative assemblies, the public press and the voices of leading statesmen, told them that the Southern States had a cause, and that while one only might lead, others would eagerly follow, the North then awoke from her dream, and the whole truth now flashes upon them. Commissioners may be sent to the South—as New York city proposes—men like Fillmore and Bronson, whom the South loves and respects—but it is too late. The North had fair warning before the election. The evil cannot be repaired now that the warning has been unheeded, and the threat of Northern domination insolently flung in our faces. Louisiana, in common with the other Gulf States, to-day sends greeting to her Palmetto sister, and will be but little behind her in the new struggle for political equality and independence which our manhood and our honor compel us to make.