The President of the United States, in his message to Congress, December, 1837, says, "The large force under Commodore Dallas, (on the West India station,) has been most actively and efficiently employed in protecting our commerce, IN PREVENTING THE IMPORTATION OF SLAVES," &c. &c.

The New Orleans Courier of 15th February, 1839, has these remarks:

"It is believed that African negroes have been repeatedly introduced into the United States. The number and the proximity of the Florida ports to the island of Cuba, make it no difficult matter; nor is our extended frontier on the Sabine and Red rivers, at all unfavorable to the smuggler. Human laws have, in all countries and ages, been violated whenever the inducements to do so afforded hopes of great profit.

"The United States' law against the importation of Africans, could it be strictly enforced, might in a few years give the sugar and cotton planters of Texas advantage over those of this state; as it would, we apprehend, enable the former, under a stable government, to furnish cotton and sugar at a lower price than we can do. When giving publicity to such reflections as the subject seems to suggest, we protest against being considered advocates for any violation of the laws of our country. Every good citizen must respect those laws, notwithstanding we may deem them likely to be evaded by men less scrupulous."

That both the south and north swarm with men 'less scrupulous,' every one knows.

The Norfolk (Va.) Beacon, of June 8, 1837, has the following:

"Slave Trade.—Eight African negroes have been taken into custody, at Apalachicola, by the U.S. Deputy Marshal, alleged to have been imported from Cuba, on board the schooner Emperor, Captain Cox. Indictments for piracy, under the acts for the suppression of the slave trade, have been found against Captain Cox, and other parties implicated. The negroes were bought in Cuba by a Frenchman named Malherbe, formerly a resident of Tallahassee, who was drowned soon after the arrival of the schooner."

The following testimony of Rev. Horace Moulton, now a minister of the Methodist Episcopal Church, in Marlborough, Mass., who resided some years in Georgia, reveals some of the secrets of the slave-smugglers, and the connivance of the Georgia authorities at their doings. It is contained in a letter dated February 24, 1839.

"The foreign slave-trade was carried on to some considerable extent when I was at the south, notwithstanding a law had been made some ten years previous to this, making this traffic piracy on the high seas. I was somewhat acquainted with the secrets of this traffic, and, I suppose, I might have engaged in it, had I so desired. Were you to visit all the plantations in South Carolina, Georgia, Alabama, and Mississippi, I think you would be convinced that the horrors of the traffic in human flesh have not yet ceased. I was surprised to find so many that could not speak English among the slaves, until the mystery was explained. This was done, when I learned that slave-cargoes were landed on the coast of Florida, not a thousand miles from St. Augustine. They could, and can still, in my opinion, be landed as safely on this coast as in any port of this continent. You can imagine for yourself how easy it was to carry on the traffic between this place and the West Indies. When landed on the coast of Florida, it is an easy matter to distribute them throughout the more southern states. The law which makes it piracy to traffic in the foreign slave trade is a dead letter; and I doubt not it has been so in the more southern states ever since it was enacted. For you can perceive at once, that interested men, who believe the colored man is so much better off here than he possibly can be in Africa, will not hesitate to kidnap the blacks whenever an opportunity presents itself. I will notice one fact that came under my own observation, which will convince you that the horrors of the foreign slave-trade have not yet ceased among our southern gentry. It is as follows. A slave ship, which I have reason to believe was employed by southern men, came near the port of Savannah with about FIVE HUNDRED SLAVES, from Guinea and Congo. It was said that the ship was driven there by contrary winds; and the crew, pretending to be short of provisions, run the ship into a by place, near the shore, between Tybee Light and Darien, to recruit their stores. Well, as Providence would have it, the revenue cutter, at that time taking a trip along the coast, fell in with this slave ship, took her as a prize, and brought her up into the port of Savannah. The cargo of human chattels was unloaded, and the captives were placed in an old barracks, in the fort of Savannah, under the protection of the city authorities, they pretending that they should return them all to their native country again, as soon as a convenient opportunity presented itself. The ship's crew of course were arrested, and confined in jail. Now for the sequel of this history. About one third part of the negroes died in a few weeks after they were landed, in seasoning, so called, or in becoming acclimated—or, as I should think, a distemper broke out among them, and they died like the Israelites when smitten with the plague. Those who did not die in seasoning, must be hired out a little while, to be sure, as the city authorities could not afford to keep them on expense doing nothing. As it happened, the man in whose employ I was when the cargo of human beings arrived, hired some twenty or thirty of them, and put them under my care. They continued with me until the sickly season drove me off to the north. I soon returned, but could not hear a word about the crew of pirates. They had something like a mock trial, as I should think, for no one, as I ever learned, was condemned, fined, or censured. But where were the poor captives, who were going to be returned to Africa by the city authorities, as soon as they could make it convenient? Oh, forsooth, those of whom I spoke, being under my care, were tugging away for the same man; the remainder were scattered about among different planters. When I returned to the north again, the next year, the city authorities had not, down to that time; made it convenient to return these poor victims. The fact is, they belonged there; and, in my opinion, they were designed to be landed near by the place where the revenue cutter seized them. Probably those very planters for whom they were originally designed received them; and still there was a pretence kept up that they would be returned to Africa. This must have been done, that the consciences of those might be quieted, who were looking for justice to be administered to these poor captives. It is easy for a company of slaveholders, who desire to traffic in human flesh, to fit out a vessel, under Spanish colors, and then go prowling about the African coast for the victims of their lusts. If all the facts with relation to the African slave-trade, now secretly carried on at the south, could be disclosed, the people of the free states would be filled with amazement."

It is plain, from the nature of this trade, and the circumstances under which it is carried on, that the number of slaves imported would be likely to be estimated far below the truth. There can be little doubt that the estimate of Mr. Wright, of Maryland, (fifteen thousand annually,) is some thousands too small. But even according to his estimate, the African slave-trade adds ONE HUNDRED AND FIFTY THOUSAND SLAVES TO EACH UNITED STATES' CENSUS. These are in the prime of life, and their children would swell the slave population many thousands annually—thus making a great addition to each census.

4. It is a notorious fact, that large numbers of free colored persons are kidnapped every year in the free states, taken to the south, and sold as slaves.