Nothing is more significant in the history of the English in America than the rapid evolution of their spacial ideals, their abandonment of the small territorial conception brought with them from the mother country and embodied, for example, in that munificent land grant, fifty by a hundred miles in extent, of the first Virginia charter in 1606, and their progress to schemes of continental expansion. Every accession of territory to the Thirteen Colonies and to the Republic gave an impulse to growth. Expansion kept pace with opportunity. Only in small and isolated New England did the contracted provincial point of view persist. It manifested itself in a narrow policy of concentration and curtailment, which acquiesced in the occlusion of the Mississippi River to the Trans-Allegheny settlements by Spain in 1787, and which later opposed the purchase of the Louisiana territory[322] and the acquisition of the Philippines. All peoples who have achieved wide expansion have developed in the process vast territorial policies. This is true of the pastoral nomads who in different epochs have inundated Europe, northern Africa and the peripheral lands of Asia, and of the great colonial nations who in a few decades have brought continents under their dominion. In nomadic hordes it is based upon habitual mobility and the possession of herds, which are at once incentive and means for extending the geographical horizon; but it suffers from the evanescent character of nomadic political organization, and the tendency toward dismemberment bred in all pastoral life by dispersal over scattered grazing grounds. Hence the empires set up by nomad conquerors like the Saracens and Tartars soon fall apart. [Sidenote: Colonial expansion.]