Final answer:
The antebellum two-party system, consisting of Democrats and Whigs, centered around issues such as the common citizen's interests and the economy, with the future of slavery being a critical unresolved issue. Contrarily, the Gilded Age two-party system saw weakened presidential power, Congress influenced by patronage, and the emergence of new political movements in response to industrial changes and societal needs.
Step-by-step explanation:
The antebellum two-party system in the United States and the Gilded Age two-party system reflect different historical contexts and political dynamics. During the antebellum era, the Democrats and Whigs emerged as major political entities following Andrew Jackson's presidency. The Democrats advocated for the popular majority and the common citizen's interests, while the Whigs supported nationalist tendencies and economic growth driven by the government. The era's critical issue, which was not resolved within the second party system, was the future of slavery.
As the Gilded Age unfolded, the political landscape shifted. The power of the presidency was limited due to highly contested elections and thinly spread popular majorities, resulting in presidents who won the Electoral College without a popular majority. The Congress of the time was heavily influenced by political patronage, impeding effective governance. This led to frustration among the populace and the rise of new political movements, as citizens sought solutions outside the traditional party structures to address contemporary issues like industrial change and workers' rights.