Sectionalism was furthered by changes in the Northern economy and politics. The development of industry in the North attracted European immigrants to jobs there. The resulting growth of population allowed the Northern states to have a larger representation in the House of Representatives. Another political party that supported a strong national government, called the Whigs, emerged to compete with Democrats, many of whom were southerners, for control of the presidency and Congress. Concern over the North’s greater voice in Congress led the South to compete rigorously for the admission of new states as slave states in order to maintain the balance of slave and free states in the Senate.