What event is often cited as the starting point of U.S. imperialism?

The Spanish-American War is often cited as the starting point of U.S. imperialism because it marked a significant shift in American foreign policy, showcasing the nation's willingness to engage in overseas expansion and assert its influence beyond its continental borders. This conflict, which took place in 1898, resulted in the U.S. defeating Spain and subsequently acquiring territories like Puerto Rico, Guam, and the Philippines. The war illustrated America's transition from a nation focused primarily on continental expansion to one that sought to acquire and govern colonies, reflecting the growing sentiment of Manifest Destiny being applied on a global scale.

In the aftermath of the war, the United States emerged as a new power on the world stage, demonstrating its military capabilities and willingness to intervene in other nations' affairs. The Treaty of Paris, which ended the war, formalized these acquisitions, signaling a commitment to imperialist policies and expanding America’s role as a global leader. This event catalyzed debates about colonialism, citizenship, and the moral implications of empire, which would continue to shape U.S. foreign policy in the years that followed.