The so-called “Era of Good Feelings” Monroe ushered in posed its own test. The decline of the Federalist Party had left Monroe’s Democratic-Republicans dominant, producing a period of relative national unity; when Monroe stood for reelection in 1820, he swept every state in the Union. But governing without a robust opposition required restraint and vigilance, as well as a steady hand to balance individual liberty with collective strength.
Perhaps nowhere was the challenge of post-revolutionary leadership more fraught than with the issue of slavery. Monroe had helped negotiate the Louisiana Purchase from France—doubling the size of the United States. Expansion, however, magnified a problem independence had left unresolved. When Missouri became the first state from the Louisiana Territory to petition to join the union, the question of whether to allow slavery into the new territories threatened to upset the delicate sectional balance between free and slave states and potentially sunder the infant nation. By admitting both Missouri and Maine into the union—one slave, one free—the Missouri Compromise of 1820 shelved the dispute long enough to buy time for the fragile nation.
Even with many of the Framers still living, the United States under Monroe grappled with how to apply the blueprint of the Constitution to the evolving needs of the nation. Projects such as the Cumberland Road—the country’s first-federally funded highway—promised to bind the republic together by facilitating westward expansion and economic integration yet also surfaced unresolved questions about the scope of federal power. Believing that Congress lacked the authority to administer and regulate infrastructure like the Cumberland, Monroe vetoed legislation authorizing the federal collection of tolls, before changing his mind and approving such a system. A similar tension emerged in the aftermath of the Panic of 1819, the nation’s first major financial crisis, when Monroe—despite public anger and lingering unease over Congress’s power to charter a national bank—supported the stabilizing role of the Second Bank of the United States. Many of the nation’s landmark Supreme Court cases were decided during this period.
It was in the United States’ relations with foreign powers, however, that Monroe left his greatest mark. Having helped to purchase Louisiana from the French, the nationalistic Monroe—and his similarly nationalistic secretary of state, John Quincy Adams—exploited the outbreak of revolution in Spain’s Latin American colonies to acquire Florida from the Spanish. In 1823, Monroe went further, declaring the Western Hemisphere off-limits to European colonization and asserting the United States as protector of the Americas. It would be decades before the United States was militarily strong enough to enforce this so-called Monroe Doctrine. Still, it became a cornerstone of United States foreign policy, reflecting Monroe’s vision of a confident nation and anticipating America’s rise as a global power.