MR. PRESIDENT, the whole subject of slavery, so far as it is involved in the issue now before the country, is narrowed down at last to a controversy on the solitary point, whether it be competent for the Congress of the United States, directly or indirectly, to exclude slavery from the Territories of the Union. The Supreme Court of the United States have given a negative answer to this proposition, and it shall be my first effort to support that negation by argument, independently of the authority of the decision. It seems to me that the radical, fundamental error which underlies the argument in affirmation of this power, is the assumption that slavery is the creature of the statute law of the several States where it is established; that it has no existence outside of the limits of those States; that slaves are not property beyond those limits; and that property in slaves is neither recognized nor protected by the Constitution of the United States, nor by international law. I controvert all these propositions, and shall proceed at once to my argument. Mr. President, the thirteen colonies, which on the 4th of July, 1776, asserted their independence, were British colonies, governed by British laws. Our ancestors in their emigration to this country brought with them the common law of England as their birthright. They adopted its principles for their government so far as it was not incompatible with the peculiarities of their situation in a rude and unsettled country. Great Britain then having the sovereignty over the colonies, possessed undoubted power to regulate their institutions, to control their commerce, and to give laws to their intercourse, both with the mother and the other nations of the earth. If I can show, as I hope to be able to establish to the satisfaction of the Senate, that the nation thus exercising sovereign power over these thirteen colonies did establish slavery in them, did maintain and protect the institution, did originate and carry on the slave trade, did support and foster that trade, that it forbade the colonies permission either to emancipate or export their slaves, that it prohibited them from inaugurating any legislation in diminution or discouragement of the institution--nay, sir, more, if, at the date of our Revolution I can show that African slavery existed in England as it did on this continent, if I can show that slaves were sold upon the slave mart, in the Exchange and other public places of resort in the city of London as they were on this continent, then I shall not hazard too much in the assertion that slavery was the common law of the thirteen States of the Confederacy at the time they burst the bonds that united them to the mother country. * * * * *