That none but domestic slaves would be introduced into Missouri, and the other new and frontier States, is most fully disproved by the thousands of fresh slaves, which, in violation of our laws, are annually imported into Alabama, Louisiana, and Mississippi. We may renew our efforts, and enact new laws with heavier penalties against the importation of slaves: the revenue cutters may more diligently watch our shores, and the naval force may be employed on the coast of Africa, and on the ocean, to break up the slave trade--but these means will not put an end to it; so long as markets are open for the purchase of slaves, so long they will be supplied;--and so long as we permit the existence of slavery in our new and frontier States, so long slave markets will exist. The plea of humanity is equally inadmissible, since no one who has ever witnessed the experiment will believe that the condition of slaves is made better by the breaking up, and separation of their families, nor by their removal from the old States to the new ones; and the objection to the provision of the bill, excluding slavery from Missouri, is equally applicable to the like prohibitions of the old States: these should be revoked, in order that the slaves now confined to certain States, may, for their health and comfort, and multiplication, be spread over the whole Union. Slavery cannot exist in Missouri without the consent of Congress; the question may therefore be considered, in certain lights, as a new one, it being the first instance in which an inquiry respecting slavery, in a case so free from the influence of the ancient laws, usages, and manners of the country, has come before the Senate. The territory of Missouri is beyond our ancient limits, and the inquiry whether slavery shall exist there, is open to many of the arguments that might be employed, had slavery never existed within the United States. It is a question of no ordinary importance. Freedom and slavery are the parties which stand this day before the Senate; and upon its decision the empire of the one or the other will be established in the new State which we are about to admit into the Union.