The Mason-Dixon Line is a convenient but an often misleading geographical division. It has been used not only to distinguish the Old South from the North and the Confederacy from the Union but to dramatize essential differences in the treatment of, and attitudes toward, the Negro - to contrast southern racial inhumanity with northern benevolence and liberality. But the historian must be wary of such an over-simplified comparison, for it does not accord with the realities of either the nineteenth or the twentieth century. The inherent cruelty and violence of southern slavery requires no further demonstration, but this does not prove northern humanity. Although slavery eventually confined itself to the region below the Mason-Dixon Line, discrimination against the Negro and a firmly held belief in the superiority of the white race were not restricted to one section but were shared by an overwhelming majority of white Americans in both the North and the South. Abraham Lincoln, in his vigorous support of both white supremacy and denial of equal rights for Negroes, simply gave expression to almost universal American convictions. In the ante bellum North racial discrimination was not as subtle or as concealed as it has been in more recent decades.