Location, therefore, while it is the most important single geographic factor, is at the same time the one most subject to the vicissitudes attending the anthropo-geographical evolution of the earth.  Its value changes with the transfer of the seats of the higher civilizations from sub-tropical to temperate lands; from the margin of enclosed sea to the hem of the open ocean; from small, naturally defined territories to large, elastic areas; from mere periphery to a combination of periphery and interior, commanding at once the freedom of the sea and the resources of a wide hinterland.

[Sidenote:  Contrasted historical sides.]

Even in Europe, however, where the Atlantic leaning of all the states is so marked as to suggest a certain dependence, the strength of this one-sided attraction is weakened by the complexity and closeness of the vicinal grouping of the several nations.  Germany’s reliance upon the neighboring grain fields of Russia and Hungary and the leather of the southern steppes counteracts somewhat the far-off magnet of America’s wheat and cattle.  England experienced a radical change of geographic front with the sailing of the Cabots; but the enormous tonnage entering and passing from the North Sea and Channel ports for her European trade[258] show the attraction of the nearby Continent.  Oftentimes we find two sides of a country each playing simultaneously a different, yet an equally important historical part, and thus distributing the historical activities, while diversifying the historical development of the people.  The young United States were profoundly influenced as to national ideals and their eventual territorial career by the free, eager life and the untrammeled enterprise of its wilderness frontier beyond the Alleghenies, while through the Atlantic seaboard it was kept in steadying contact with England and the inherited ideals of the race.  Russia is subjected to different influences on its various fronts; it is progressive, industrial, socialistic on its European side in Poland; expansive and radical in a different way in colonial Siberia; aggressive in the south, bending its energies toward political expansion along the Mediterranean and Persian Gulf seaboards.  In all such countries there is a constant shifting and readjustment of extra-territorial influences.

[Sidenote:  One-sided historical relations.]

It is otherwise in states of very simple vicinal grouping, coupled with only a single country or at best two.  Spain, from the time Hamilcar Barca made it a colony of ancient Carthage, down to the decline of its Saracen conquerors, was historically linked with Africa.  Freeman calls attention to “the general law by which, in almost all periods of history, either the masters of Spain have borne rule in Africa or the masters of Africa have borne rule in Spain.”  The history of such simply located countries tends to have a correspondingly one-sided character.  Portugal’s development has been under the exclusive