There is one long-continued British intervention, which speaks now with controlling power; and it is on this account that I reserve it for the close of what I have to say on this head. Though not without original shades of dark, it has for more than half a century been a shining example to the civilized world. I refer to that _intervention against Slavery_, which, from its first adoption, has been so constant and brilliant as to make us forget the earlier _intervention in behalf of Slavery_, when, for instance, at the Peace of Utrecht, Great Britain intervened to extort the detestable privilege of supplying slaves to Spanish America at the rate of four thousand eight hundred yearly during the space of thirty years, and then again, at the Peace of Aix-la-Chapelle, higgled for a yet longer sanction of the ignoble intervention; nay, it almost makes us forget the kindred intervention, at once sordid and criminal, by which this power counteracted all efforts for the prohibition of the slave-trade even in its own colonies, and thus helped to fasten Slavery upon Virginia and Carolina. The abolition of the slave-trade by Act of Parliament, in 1807, was the signal for a change of history. A British poet at the time gave exulting expression to the grandeur of the epoch:-- “‘Thy chains are broken, Africa, be free!’ Thus saith the island-empress of the sea; Thus saith Britannia. O ye winds and waves, Waft the glad tidings to the land of slaves!”[79] Curiously, it was the other color which gained the first fruits of this revolution, by triumphant intervention for the overthrow of White Slavery in the Barbary States. The old hero of Acre, Sir Sidney Smith, released from long imprisonment in France, sought to organize a “holy league” for this purpose; the subject was discussed at the Congress of Vienna; and the agents of Spain and Portugal, anxious for the punishment of their piratical neighbors, argued, that, because Great Britain had abolished for itself the traffic in African slaves, therefore it must see that whites were no longer enslaved in the Barbary States. The argument was less logical than humane. But Great Britain undertook the work. With a fleet complete at all points, consisting of five line-of-battle ships, five frigates, four bomb-vessels, and five gun-brigs, Lord Exmouth approached Algiers, where he was joined by a considerable Dutch fleet, anxious to take part. “If force must be resorted to,” said the Admiral in general orders shortly before, “we have the consolation of knowing that we fight in the sacred cause of Humanity, and cannot fail of success.” Less than half a day was enough, with such a force in such a cause. The formidable castles of the great Slavemonger were battered to pieces, and he was compelled to sign a treaty, confirmed under a salute of twenty-one guns, which in its first article stipulated “the abolition of Christian Slavery forever.” Glorious and beneficent intervention!