AP US History question:

How did TWO of the following contribute to the reemergence of a two-party system in the period 1820-1840? Major political personalities, states' rights, economic issues.

In terms of the reemergence of a two-party system in the period 1820-1840, the key factors were really about slavery and economic issues, with the Democrats favoring slavery as a legitimate economic means to an end in the South, and the Republicans viewing it as a moral evil.