During the American Civil War, slaves who sought refuge in Union army military camps or who lived in territories that fell under Union control were declared contraband. This policy was first used by General Benjamin F. Butler in 1861, in what came to be known as the "Fort Monroe Doctrine," established in Hampton, Virginia. By war's end, the Union had set up 100 contraband camps in the Southern United States. The Roanoke Island Freedmen's Colony (1863–1867) was developed to be a colony. Many adult former slaves worked for wages for the Army at such camps.