They were not even, primarily, independent states in the making. The fact that a few of them, which happened to have a continent at their back and unlimited room for expansion, revolted after a century and a half, has tended to obscure their real contemporary relation to England, much as the refraction of water alters the apparent position of objects under it when seen from an angle. The angle from which we Americans always look at the original colonies is that of our present independent nation; but by doing so we unwittingly shift their position from integral parts of a complicated imperial system to incipient independent commonwealths, assumed to have been unjustly held in thraldom. Needless to say, such a viewpoint vitiates our appraisal of every contemporary act and opinion. It is possible that after some hundreds of years the present United States may be divided into two or more nations; but to-day they form one system, and no one would think of interpreting the present relations between North and South, or East and West, in the light of a possible separation centuries hence. In the same way, the relations between England and her colonies in the seventeenth century should be interpreted in the light of their then actual and prospective union and the political theories current, and not in that of a subsequent, and more or less accidental, separation, and of the wholly different theories of a later age.[714] Footnote 714: I speak of the separation as accidental, not because the forces then at work did not make it almost inevitable, but because altered economic theories and scientific discoveries, the latter largely eliminating the extremely important elements, in the original problem, of time and distance, occurred a half-century after the separation took place. Had they occurred sooner, they might have prevented it, as they have been largely instrumental in holding the remainder of the empire together and greatly adding to it. The influence of free-trade, steam, and electricity has been of vast importance in imperial politics.