As was natural, the professional classes of the South, the lawyers, clergymen, physicians, and teachers, were in close alliance with the planters, their callings and their incomes being directly dependent on them. A successful professional man soon became a master and usually retired to a country seat. If a poor but capable young man gave promise of power and leadership he was soon accepted by his dominant neighbors and became a son-in-law of a privileged family; if a preacher rose to fame doubting or even condemning the institutions of the South, he was apt to find a way to change his views and to become a part of the system before he reached his mature years. The articulate South was, therefore, in economic and social life a unit in 1845, and this unit was the strongest group in the country as a whole. Its demand for expansion towards the southwest was based upon the common desire, the common law of growth, and this growth was the only means of winning new votes in Congress and in the electoral college. It was the same motive which actuated the farmers of the Northwest and the commercial leaders of New England when they demanded of the Federal Government the seizure of Oregon or the protection of ships upon the ocean. [Illustration: Wheat Areas in 1840] If the planter and dominant element of the South urged Polk and Walker onward in their course and gave power to Calhoun, the greater masses of non-slaveholding Southerners were hardly less enthusiastic. The earlier jealousy and fear of the planters had everywhere weakened as the new lands of the South and West gave opportunity to the more ambitious to rise in the social and economic scale. The sons of small farmers and landless men in the old South had built the cotton kingdom of the lower South, and were now drawing aristocratic Virginia and the Carolinas into a close union with the new region. The widening of the area of slavery was equivalent to the opening of a social safety valve to the older and stratifying life of the South. Young men who had been hostile to slavery at home became friendly allies in a new environment. Thus the small farmers became enthusiastic supporters of the great machine of which slavery was the base.