Where they are similar is the breaking of Federal law to aid fugitives.
And the people helping the illegals think it is immoral to keep them out.
The question is "Is it okay to break Federal law if you feel it is morally the right thing to do?"
Again, you are comparing apples and oranges and making a ‘Heels Up Harris’ word fruit salad.
Illegals are breaking the law the minute they step onto US soil, uninvited. Those aiding them should be held accountable, including the ‘coyotes’ that helped them get here and those that harbor them or fight against ICE officers who are trying to deport them.
Those aiding slaves were aiding human beings, brought here against their will (or born into it) to escape slavery.
Apples and oranges.