But no truth of history is more evident than that the authors of the Constitution regarded slavery as impossible to be sustained upon the ground of the natural rights of mankind, and deserving of no encouragement in the Territories, or States hereafter to come into the Union. It was thought that the best interests of the slave States would lead them to abolish slavery, and that before many years, the Republic would cease to bear the disgrace of chattel bondage. It is certainly proper that the acts and language of the authors of the Constitution, and those who chiefly were instrumental in achieving our independence, should be made to interpret that instrument which was the creation of their own toils and love of country. Because the circumstances of the present day have brought about a mighty change in the feelings and opinions of the slave States, it does not follow that the Constitution in its original intention and spirit should be accommodated to this new aspect of things. It is easy to get up a theory of the natural right of slavery, and then say that the Constitution meant that the slave States should carry slave property just where the free States carry their property; but when this ground is taken, the Constitution is made, to all intents, a pro-slavery instrument. It ceases to be the charter of a nation’s freedom, and resolves itself into the most effective agent of the propagandism of slavery. The transition is easy from such a theory to the fulfillment of the boast of Senator Toombs, ’that the roll of slaves might yet be called at the foot of Bunker Hill Monument.’ But no straining of the language of the Constitution can make it mean the recognition of the natural right of slavery, The guarded manner in which the provision was made for the rendition of slaves, and all the circumstances connected with the adoption of the Constitution, show conclusively that slavery was considered only a local and municipal institution, a serious evil, to be suppressed and curtailed by the slave States, and never by the General Government a blessing to be fostered and extended where it did not exist at the time the Union of the thirteen States was perfected.