The more flat and featureless a lowland is, the more important become even the slightest surface irregularities which can draw faint dividing lines among the population. Here a gentle land-swell, river, lake, forest, or water-soaked moor serves as boundary. Especially apparent is the differentiating influence of difference of soils. Gravel and alluvium, sand and clay, chalk and more recent marine sediments, emphasize small geographical differences throughout the North German lowland and its extension through Belgium and Holland; here various soils differentiate the distribution of population. In the Netherlands we find the Frisian element of the Dutch people inhabiting chiefly the clay soils and low fens of the west and northwest, the Saxon in the diluvial tracts of the east, and the Frankish in the river clays and diluvium of the south. All the types have maintained their differences of dialect, styles of houses, racial character, dress and custom.[1043] The only distinctive region in the great western lowland of France, which comprises over half of the country, is Brittany, individualized in its people and history by its peninsula form, its remote western location, and its infertile soil of primary rocks. Within the sedimentary trough of the Paris Basin, a slight Cretacean platform like the meadow land of Perche[1044] (200 to 300 meters elevation) introduces an area of thin population devoted to horse and cattle raising in close proximity to the teeming urban life of Paris. The eastern lowland of England also can be differentiated economically and historically chiefly according to differences of underlying rocks, Carboniferous, Triassic, Jurassic, chalk, boulder clays, and alluvium, which also coincide often with slight variations of relief.[1045] In Russia the contrast between the glaciated surface of the north and the Black Mould belt of the south makes the only natural divisions of that vast country, unless we distinguish also the arid southeastern steppes on the basis of a purely climatic difference. [See map page 484.]
The broad coastal plain of our South Atlantic States contains only low reliefs; but it is diversified by several soil belts, which exert a definite control over the industries of the inhabitants, and thereby over the distribution of the negro population. In Georgia, for instance, the rich alluvial soil of the swampy coast is devoted to the culture of rice and sea-island cotton, and contains over 60 per cent. of negroes in its population. This belt, which is only 25 miles wide, is succeeded inland by a broader zone of sandy pine barrens, where the proportion of negroes drops to only 20 or 30 per cent. of the total. Yet further inland is another fertile belt, devoted chiefly to the cultivation of upland cotton and harboring from 35 to over 60 per cent. of negroes in its population.[1046] Alabama shows a similar stratification of soils and population from north to south over its level surface. Along the northern border of the state the cereal belt coincides with the deep calcareous soil of the Tennessee River Valley, where negroes constitute from 35 to 60 per cent. of the inhabitants. Next comes the mineral belt, covering the low foot-hills of the Appalachian Mountains. It contains the densest population of the state, less than 17 per cent. of which is negro. South of this is the broad cotton belt of various rich soils, chiefly deep black loam of the river bottoms, which stretches east and west across the state and includes over 60 per cent. of negroes in its population. This is succeeded by the low, coastal timber belt, marked by a decline in the quality of the soil and the proportion of negro inhabitants.[1047]
Value of slight elevations.
In the dead level of extensive plains even slight elevations are seized upon for special uses, or acquire peculiar significance. The Kurgans or burial mounds of the prehistoric inhabitants of Russia, often twenty to fifty feet high, serve to-day as watch-towers for herdsmen tending their flocks.[1048] Similarly the Bou-bous, inhabiting the flat grasslands of the French Congo between the Shari and Ubangui Rivers, use the low knolls dotted over their country, probably old ant-hills, as lookout points against raiders.[1049] The sand hills and ridges which border the southern edges of the North German lowland form districts sharply contrasted to the swampy, wooded depressions of the old deserted river valleys just to the north. Early occupied by a German stock, they furnished the first German colonists to displace the primitive Slav population surviving in those unattractive, inaccessible regions, as seen in the Spreewald near Kottbus to-day.
Plains and political expansion.
The boundless horizon which is unfavorable to a nascent people endows them in their belated maturity with the power of mastering large areas. Political expansion is the dominant characteristic of the peoples of the plains. Haxthausen observed that handicapped and retarded Russia commands every geographic condition and national trait necessary for virile and expansive political power.[1050] Muscovite expansion eastward across the lowlands of Europe and Asia is paralleled by the rapid spread of American settlement and dominion across the plains and prairies of the Mississippi Valley, and Hungarian domination of the wide Danubian levels from the foot-hills of the Austrian Alps to the far Carpathian watershed. It was the closely linked lowlands of the Seine and Loire which formed the core of political expansion and centralization in France. Nearly the whole northern lowland of Germany has been gradually absorbed by the kingdom of Prussia, which now comprises in its territory almost two-thirds of the total area of the Empire. Prussian statesmen formulated the policy of German unification and colonial expansion, and to Prussia fell the hereditary headship of the Empire.
Lowland states tend to stretch out and out to boundaries which depend more upon the reach of the central authority than upon physical features. We have seen American settlement and dominion overleap one natural boundary after another between the Mississippi River and the Pacific, from 1804 to 1848. Russia in an equally short period has pushed forward its Asiatic frontier at a dozen points, despite all barriers of desert and mountain. Argentina, blessed with extensive plains, fertile soil and temperate climate, which have served to augment its population both by natural increase and steady immigration (one-fourth of its population is foreign), has expanded across the Rio Negro over the grasslands of the Patagonian plain, and thereby enlarged its area by 259,620 square miles since 1881. The statesman of the plains is a nature-made imperialist; he nurses wide territorial policies and draws his frontiers for the future. To him a "far-flung battle line" is significant only as a means to secure a far-flung boundary line.