What crop made the South an economic powerhouse and expanded
slavery in the process?

Production exploded: Between 1801 and 1835 alone, the U.S. cotton exports grew from 100,000 bales to more than a million, comprising half of all U.S. exports. The upshot: As cotton became the backbone of the Southern economy, slavery drove impressive profits.

Explanation:

the two major parties acting together and cooperating when making decisions is bipartisan