To this may be added the testimony of the present Vice President of the United States, Hon. Richard M. Johnson, of Kentucky.  In a speech before the United States’ Senate, February 1, 1820, (National Intelligencer, April 29, 1820,) he says:  “Congress has the express power stipulated by the Constitution, to exercise exclusive legislation over this District of ten miles square.  Here slavery is sanctioned by law.  In the District of Columbia, containing a population of 30,000 souls, and probably as many slaves as the whole territory of Missouri, THE POWER OF PROVIDING FOR THEIR EMANCIPATION RESTS WITH CONGRESS ALONE.  Why, then, let me ask, Mr. President, why all this sensibility—­this commiseration—­this heart-rending sympathy for the slaves of Missouri, and this cold insensibility, this eternal apathy, towards the slaves in the District of Columbia?”

It is quite unnecessary to add, that the most distinguished northern statesmen of both political parties, have always affirmed the power of Congress to abolish slavery in the District.  President Van Buren in his letter of March 6, 1836, to a committee of gentlemen in North Carolina, says, “I would not, from the light now before me, feel myself safe in pronouncing that Congress does not possess the power of abolishing slavery in the District of Columbia.”  This declaration of the President is consistent with his avowed sentiments touching the Missouri question, on which he coincided with such men as Daniel D. Tompkins, De Witt Clinton, and others, whose names are a host.[A] It is consistent also, with his recommendation in his late message on the 5th of last month, in which, speaking of the District, he strongly urges upon Congress “a thorough and careful revision of its local government,” speaks of the “entire dependence” of the people of the District “upon Congress,” recommends that a “uniform system of local government” be adopted, and adds, that “although it was selected as the seat of the General Government, the site of its public edifices, the depository of its archives, and the residence of officers intrusted with large amounts of public property, and the management of public business, yet it never has been subjected to, or received, that special and comprehensive legislation which these circumstances peculiarly demanded.”

[Footnote A:  Mr. Van Buren, when a member of the Senate of New-York, voted for the following preamble and resolutions, which passed unanimously:—­Jan. 28th, 1820.  “Whereas, the inhibiting the further extension of slavery in the United States, is a subject of deep concern to the people of this state:  and whereas, we consider slavery as an evil much to be deplored, and that every constitutional barrier should be interposed to prevent its further extension:  and that the constitution of the United States clearly gives congress the right to require new states, not comprised within the original boundary of the United States, to make the prohibition of slavery a condition of their admission into the Union:  Therefore,