The United States Constitution says nothing about political parties. George Washington and other Founders feared factions would create conflict and paralysis, but disagreements over federal power soon made organized parties necessary. Alexander Hamilton’s Federalists supported a strong central government, commerce, industry, and close ties to Britain. Thomas Jefferson and James Madison’s opponents favored a decentralized agrarian republic. Jeffersonians won power in 1800, and the first party system faded after the War of 1812.
Andrew Jackson’s movement created the modern Democratic Party, while his opponents formed the Whigs. Their battles centered on executive power, banking, tariffs, modernization, and federal patronage. Slavery shattered the Whigs in the 1850s and helped produce the anti-slavery Republican Party, which rose with Abraham Lincoln and became dominant after the Civil War.
The Great Depression triggered another transformation. Franklin Roosevelt’s New Deal built a Democratic coalition of labor, urban voters, immigrants, African Americans, farmers, and reformers around expanded federal government. Civil rights legislation under Lyndon Johnson then accelerated the movement of white Southern voters toward the Republican Party. By the Reagan era, Republicans emphasized smaller government, tax cuts, social conservatism, and strong military policy, while Democrats increasingly drew support from urban, non-white, union, and college-educated voters.
Since 2016, Republicans have increasingly emphasized cultural conservatism, nationalism, opposition to globalization, and distrust of institutions. Meanwhile, third parties such as the Libertarians and Greens remain active, especially locally. The two-party system is reinforced by winner-take-all elections, ballot-access barriers, and party labels, though weak national control allows major internal factions. The result is a system that looks like two parties but contains many competing coalitions.