The Tenth Amendment says that the powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people. The Constitution nowhere says that states have no right to secede.
"Under this Constitution, as originally adopted and as it now exists, no State has power to withdraw from the jurisdiction of the United States; and this Constitution, and all laws passed in pursuance of its delegated powers, are the supreme late [sp?] of the land, anything contained in any constitution, ordinance, or act of any State to the contrary notwithstanding."
28 nays to 18 yeas
Link. (courtesy FReeper Idabilly, who posted it to another thread last March)
The new Constitution was intended to be "perpetual" and "forever."
The Founders considered disolving the Union a possibility, but only by mutual consent, or by "usurpations" or "abuses" having that same effect.
In December 1860, when South Carolina first seceded, there were no "usurpations", no "abuses" "injuries" or "oppressions" that might remotely justify secession.
And when you read the South's reasons for secessions, it all boils down to their fears about what the new Abolitionist Republicans might do in the future.
And Southerners did not just secede, they also provoked and then declared war on the United States.