[DoodleDawg]

What part of the constitution gives him the power to do this? I would think this is flatly contradicted by Article IV, Section 2.

The Confiscation Acts of 1861 and 1862, upheld by the Supreme Court.

[DiogenesLamp]

Overrides Article IV, Section 2, does it? Pretty neat trick for a law passed by Congress to actually override the Constitution itself.

[BroJoeK]

DiogenesLamp: "What part of the constitution gives him the power to do this? I would think this is flatly contradicted by Article IV, Section 2."

DoodleDawg: "The Confiscation Acts of 1861 and 1862, upheld by the Supreme Court."

People in rebellion, or at war against the United States, did not receive full protection of the Constitution, especially in matters relating to confiscations & "contraband".
This was true even in the Revolutionary War regarding loyalists.

Also, somewhere I've read, in the First Seminole War, Florida, circa 1818, when James Monroe was President, young John Quincy Adams Secretary of State, and Andrew Jackson in command of US forces invading Spanish Florida.
One of Jackson's actions was to declare slaves of Spaniards freed.
Iirc, Jackson's precedent was recalled by old Adams to young Congressman Lincoln, in 1847.

So it was well understood that people in rebellion could have their property confiscated, including contraband slaves.

And indeed, Confederates themselves practiced contraband confiscations in Unionist regions, to including grabbing any Union blacks they could for return to Confederate slave markets.