Now this is precisely the case before us. Congress, in attempting to reënact the Maryland laws, to uphold slavery in this District, transcended the limits of its constitutional power. It acted unconstitutionally. It acted in plain contravention of some of the plainest and most obvious principles consecrated by the constitution. If so, no one will dispute that its act is void. I do not deny, then, that Congress used words of sufficient amplitude to cover slavery; but what I deny is, that it had any power to give legal force to those words. 5. My next proposition, therefore, is this: _That as Congress can do nothing excepting what it is empowered to do by the constitution, and as the constitution does not empower it to establish slavery here, it cannot establish slavery here, nor continue it._ Where is there any _express_ power given to Congress by the constitution to establish slavery? Where is the article, section, or clause? I demand to have the title shown. Thousands of human beings are not to be robbed of all their dearest rights, and they and their children, forever, by strained constitutions, or apocryphal authority, doomed to bondage. Will those who say that Congress cannot establish a banking institution by construction, nor aid internal improvements, nor enact a tariff,--will they say that Congress can make a man a slave, and all his posterity slaves, by construction? Nor can any power to establish slavery be deduced from the 18th clause of the 8th section of the 1st article of the constitution, which gives Congress power “to make all laws which shall be necessary and proper for carrying into execution” the powers that are granted. What power is granted to Congress, for the exercise of which the establishment of slavery in this District is a necessary means or a preliminary? Congress has power to lay and collect taxes; to borrow money; to regulate commerce; to establish uniform rules of naturalization; to coin money; to punish counterfeiters; to establish post offices and post roads; to promote the progress of science and the arts; to establish courts; to define and punish piracies on the high seas; to declare war; to raise and support armies; to provide and maintain a navy; to organize and maintain a militia; and so forth, and so forth. But to what one of all these powers is the power to establish slavery in the District of Columbia a necessary incident? If slavery in the District of Columbia were to cease to-day, could not the government continue to exercise every function which it has heretofore exercised? If so, then the existence of slavery in this District is not “necessary” to the exercise of any of the expressly granted powers. I call upon any gentleman to name any one power of this government which cannot be exercised, which must necessarily cease, if slavery should cease to be, in this District of Columbia? “I pause for a reply.”