This struggle reached its climax in different States at various periods. In Maryland the contest differed somewhat from that of other Southern States because of the contiguity of that commonwealth with Pennsylvania, which early set such examples of abolition and democratic government that a slave State near by could not go so far in fortifying an aristocratic governing class. In Virginia the situation was much more critical than elsewhere. Unlike the other Atlantic States, which wisely provided roads and canals to unify the diverse interests of the sections, that commonwealth left the trans-Alleghany district to continue in its own way as a center of insurgency from which war was waged against the established order of things.[21] In most States, however, the contest was decided by the invention of the cotton gin and other mechanical appliances which, in effecting an industrial revolution throughout the world, gave rise to the plantation system found profitable to supply the increasing demand for cotton. In the course of the subsequent expansion of slavery, many of the uplanders and mountaineers were gradually won to the support of that institution. Realizing gradually a community of interests with the eastern planters, their ill-feeling against them tended to diminish. Abolition societies which had once flourished among the whites of the uplands tended to decline and by 1840 there were practically no abolitionists in the South living east of the Appalachian Mountains.[22] Virginia, which showed signs of discord longer than the other Atlantic States, furnishes us a good example of how it worked out. The reform party of the West finally forced the call of a convention in 1829, hoping in vain to crush the aristocracy. Defeated in this first battle with the conservatives, they secured the call of the Reform Convention in 1850 only to find that two thirds of the State had become permanently attached to the cause of maintaining slavery.[23] Samuel McDowell Moore, of Rockbridge County in the Valley, said in the Convention of 1829-30 that slaves should be free to enjoy their natural rights,[24] but a generation later the people of that section would not have justified such an utterance in behalf of freedom. The uplanders of South Carolina were early satisfied with such changes as were made in the apportionment of representation in 1808, and in the qualifications of voters in 1810.[25] Thereafter Calhoun's party, proceeding on the theory of government by a concurrent majority, vanquished what few liberal-minded men remained, and then proceeded to force their policy on the whole country.