THE problem of the twentieth century is the problem of the color line; the relation of the darker to the lighter races of men in Asia and Africa, in America and the islands of the sea. It was a phase of this problem that caused the Civil War; and however much they who marched south and north in 1861 may have fixed on the technical points of union and local autonomy as a shibboleth, all nevertheless knew, as we know, that the question of Negro slavery was the deeper cause of the conflict. Curious it was, too, how this deeper question ever forced itself to the surface, despite effort and disclaimer. No sooner had Northern armies touched Southern soil than this old question, newly guised, sprang from the earth, — What shall be done with slaves?