This question is incomplete, here´s the complete question.
One major change in United States politics from the 1820s to the mid-1850s was the
adoption of an antislavery platform by the Whig Party
rise of political parties defined largely by regional interests
collapse of the Democratic Party in the South
decline of competition between parties
Answer: rise of political parties defined largely by regional interests
Explanation:
Beginning in the 1820s, the size of the electorate grew immensely and the United States politics rapidly changed. Since Andrew Jackson´s election in 1828, the Democrats were established as representing the alliance between small farmers, Westerners, and the working class. On the other hand, the Whig Party, created in 1834, represented businesses, a national bank, and those who wanted a strong central government.