It had been possible to preserve this balance in the Senate, where State representation is equal, by admitting a Northern and a Southern State contemporaneously. Thus two Senators from each section were created. In the House of Representatives, where strength depends upon the distribution of population, no such balance could be maintained. The attractiveness of the back lands as they were opened to settlement, the ease with which farms could be secured from the public domain, the rapid development of water-power, and the increasing immigration from Europe, caused a rapid growth of population in the trans-Alleghenian region. In 1800, only one settler had crossed the mountains to fourteen remaining on the coast-plain. Ten years later one had crossed for every six remaining behind, and in 1820 the proportion was one to four. There had been some alarm manifest in the older States in earlier times, because the power and prestige which they had enjoyed must eventually be reduced if not lost through the rapidly growing West. But whatever danger of this nature was realised became of secondary importance by 1820 to the larger question of the unequal distribution of the migrants in the various parts of the West. Between 1810 and 1820, for instance, Ohio had increased in population 151.9 per cent. and Tennessee only 61.5 per cent. For every 319 people who sought homes in Illinois during that period, only 87 had settled in Mississippi. The two States had been admitted almost simultaneously and had equal attractions. Why should the one gain more population and have more political strength than the other? Although statistics for the sparsely populated territories were not so available, there was no doubt that the Northern section everywhere was being settled more rapidly than the Southern.