The principle of this legislation had already been published to the
country in a very fortunate way by General Butler. In May, 1861, being
in command at Fortress Monroe, he had refused, under instructions from
Cameron, to return three fugitive slaves to their rebel owner, and he
had ingeniously put his refusal on the ground that they were "contraband
of war." The phrase instantly became popular. General Butler says that,
"as a lawyer, [he] was never very proud of it;" but technical inaccuracy
does not hurt the force of an epigram which expresses a sound principle.
"Contraband" underlay the Emancipation Proclamation.

Thus the slaves themselves were forcing the issue, regardless of
polities and diplomacy. With a perfectly correct instinctive insight
into the true meaning of the war, they felt that a Union camp ought to
be a place of refuge, and they sought it eagerly and in considerable
numbers. Then, however, their logical owners came and reclaimed them,
and other commanders were not so apt at retort as General Butler was.
Thus it came to pass that each general, being without instructions,
carried out his own ideas, and confusion ensued. Democratic commanders
returned slaves; Abolitionist commanders refused to do so; many were
sadly puzzled what to do. All alike created embarrassing situations for
the administration.

General Fremont led off. On August 30, being then in command of the
Western Department, he issued an order, in which he declared that he
would "assume the administrative powers of the State." Then, on the
basis of this bold assumption, he established martial law, and
pronounced the slaves of militant or active rebels to be "free men." The
mischief of this ill-advised proceeding was aggravated by the "fires of
popular enthusiasm which it kindled." The President wrote to Fremont,