His fears were realized under the post 16th Amendment Constitution, not the Constitution of 1787.
The seeds were planted in 1787 when the Federal government was given the job of policing itself. Without explicit authority given to the states, they lost the ability to reign in an out of control federal government. Before the 16th amendment, the feds decided they had the authority to wage war to maintain a forced union.
The sovereign people are charged with policing the government. The Constitution did not fail us, we have failed the Constitution.
As for 1861,
Article I Section 10: "No state shall enter into any Treaty, Alliance . . . "
Article I Section 8, Congress is empowered to . . . "suppress insurrections."