. I do not admit that there
is even among the peace powers of Congress no such authority; but in war
there are many ways by which Congress not only have the authority, but
are bound to interfere with the institution of slavery in the States.
The existing law prohibiting the importation of slaves into the United
States from foreign countries, is itself an interference with the
institution of slavery in the States. It was so considered by the
founders of the Constitution of the United States, in which it was
stipulated that Congress should not interfere, in that way, with the
institution, prior to the year 1808.

During the late war with Great Britain the military and naval commanders
of that nation issued proclamations inviting the slaves to repair to
their standards, with promises of freedom and of settlement in some of
the British colonial establishments. This, surely, was an interference
with the institution of slavery in the States. By the treaty of peace,
Great Britain stipulated to evacuate all the forts and places in the
United States, without carrying away any slaves. If the Government of
the United States had no authority to interfere, in any way, with
the institution of slavery in the States, they would not have had
the authority to require this stipulation. It is well known that
this engagement was not fulfilled by the British naval and military
commanders; that, on the contrary, they did carry away all the slaves
whom they had induced to join them, and that the British Government
inflexibly refused to restore any of them to their masters; that a claim
of indemnity was consequently instituted in behalf of the owners of the
slaves, and was successfully maintained. All that series of transactions
was an interference by Congress with the institution of slavery in the
States in one way--in the way of protection and support. It was by the
institution of slavery alone that the restitution of slaves enticed by
proclamations into the British service could be claimed as property.
But for the institution of slavery, the British commanders could neither
have allured them to their standard, nor restored them otherwise than
as liberated prisoners of war. But for the institution of slavery, there
could have been no stipulation that they should not be carried away
as property, nor any claim of indemnity for the violation of that
engagement.

But the war power of Congress over the institution of slavery in the
States is yet