Every geographical region of strongly marked character possesses a certain polarity, by reason of which it attracts certain racial or economic elements of population, and repels others. The predatory tribes of the desert are constantly reinforced by refugee outlaws from the settled agricultural communities along its borders.[284] The mountains which offer a welcome asylum for the persecuted Waldenses have no lure for the money-making Jew, who is therefore rarely found there. The negroes of the United States are more and more congregating in the Gulf States, making the "Black Belt" blacker. The fertile tidewater plains of ante-bellum Virginia and Maryland had a rich, aristocratic white population of slave-holding planters; the mountain backwoods of the Appalachian ranges, whose conditions of soil and relief were ill adapted for slave cultivation, had attracted a poorer democratic farmer class, who tilled their small holdings by their own labor and consequently entertained little sympathy for the social and economic system of the tidewater country. This is the contrast between mountain and plain which is as old as humanity. It presented problems to the legislation of Solon, and caused West Virginia to split off from the mother State during the Civil War.[285] Each contrasted district has its own polarity; but with this it attracts not one but many of the disruptive forces which are pent up in every people or state. Certain conditions of climate, soil, and tillable area in the Southern States of the Union made slave labor remunerative, while opposite conditions in the North combined eventually to exclude it thence. Slave labor in the South brought with it in turn a whole train of social and economic consequences, notably the repulsion of foreign white immigration and the development of shiftless or wasteful industrial methods, which further sharpened the contrast between the two sections. The same contrast occurs in Italian territory between Sicily and Lombardy. Here location at the two extremities of the peninsula has involved a striking difference in ethnic infusions in the two districts, different historical careers owing to different vicinal grouping, and dissimilar geographic conditions. These effects operating together and attracting other minor elements of divergence, have conspired to emphasize the already strong contrast between northern and southern Italy. [Sidenote: Geographical marks of growth.]