And yet again we see a Lost-Causer defending slavery!
But in fact, Congress provided a huge "remedy", in the form of the 1850 Fugitive Slave Act, which made Federal Government -- not the States -- responsible to return runaway slaves.
Further, the Fugitive Slave Act allowed, in effect, random searches of any African Americans in Northern states with requirements that they prove their freedom, and no opportunity to defend themselves in court.
In short, the Fugitive Slave Act went far beyond what the Constitution required, and rendered moot any Slave-Power complaints against alleged Northern "breach of compact".
And the proof of it is: so long as Southern Democrats remained in control in Washington, DC, the Slave-Power had no real problems with compliance to the Fugitive Slave Act.
You’re skinning ‘em alive.
Keep up the good work.