Short answers, pulled from the story.
The Second Party System operated from about 1828 until early 1854 when it ended. Rapidly rising levels of voter interest characterized this period through Election Day turnouts, rallies, partisan newspapers, and high personal loyalty.
Andrew Jackson formed the embryonic Democratic Party that ousted Adams in 1828 with a coalition including local militia companies and state political factions. Martin Van Buren played a key role by bringing electoral votes from Virginia and Pennsylvania to support the group.
By early 1850s question of slavery dominated political landscape causing Whig disintegration as Northern National Republicans and Southern Nullifiers held opposing views on slavery. With outbreak of Civil War in 1861 Whig party ceased to exist entirely after remaining members endorsed Know Nothing campaign of Millard Fillmore.
Catholic immigrants especially Irish and German were heavily and enthusiastically Democratic while Evangelical Protestants and English and Scots-Irish immigrants typically supported Whig candidates. In Springfield Illinois poll books showed how individuals voted indicating Whig rise occurred in 1836 before falling into Democratic hands as immigrants changed city makeup.
The Second Party System arose primarily because Jackson sought to destroy the Second Bank of the United States headquartered in Philadelphia with offices nationwide. He believed only gold and silver should circulate and issued Specie Circular of July 1836 rejecting paper money issued by banks for buying federal land.