Answer:
the Fifth Amendment.
Step-by-step explanation:
In the Scott v. Sandford case, that occurred in 1857, concerning the issue of Scott's freedom from slavery Sandford’s argument was based on the "FIFTH AMENDMENT."
This is because the fifth amendment says among other things that "... nor be deprived of life, liberty, or property, without due process of law;"
Therefore, in Scott vs Sandford's case, Sandford's argument was based on Fifth Amendment because any ban on slavery would be a violation of the Fifth Amendment, which forbade denying property rights without due process of law.