Technological advancements in the late 19th century greatly facilitated the United States' global expansion. The development of faster and more efficient steamships reduced travel times and costs, enabling easier access to international markets. The telegraph revolutionised communication, allowing for instant coordination and negotiation across vast distances. Railroads played a significant role domestically, efficiently moving goods to ports for export. These advancements not only enhanced trade but also supported military expeditions and overseas investments. Essentially, technology was a key enabler, allowing the U.S. to project its economic and military power globally more effectively than ever before.

During the late 19th century, U.S. economic interests significantly shaped its relationship with Latin American countries. The pursuit of new markets and resources led to a policy of economic interventionism in the region. The United States employed various tactics, from diplomatic agreements to outright military interventions, to secure economic interests in Latin America. This period saw the U.S. establishing control over key resources and markets, influencing Latin American economies to align with American interests. These actions often led to long-term economic dependencies and political influences in the region, reflecting the asymmetrical nature of these relationships.

Criticism of U.S. foreign policy during the late 19th century came from various quarters within the United States. Some critics argued that the focus on overseas expansion was a diversion from domestic issues, such as economic inequality and social reforms. Others opposed the moral and ethical implications of imperialism, arguing that it contradicted the nation's founding principles of liberty and self-determination. Anti-imperialists, including prominent figures like Mark Twain, raised concerns about the costs of maintaining overseas territories and the potential for entanglement in foreign conflicts. These criticisms reflected a growing debate over America's role in the world and the consequences of its expansionist policies.

Naval power played a crucial role in the United States' pursuit of global influence during the late 19th century. The U.S. Navy was instrumental in protecting and projecting American interests overseas. Influenced by Alfred Thayer Mahan's theories on the importance of a strong navy in securing global dominance, the U.S. significantly expanded and modernised its naval fleet. This expansion enabled the U.S. to exert influence in key strategic areas, protect its burgeoning international trade routes, and assert its presence in international disputes. The strengthened navy was a clear signal of America's aspirations as a global power and a vital tool in achieving those ambitions.

Social Darwinism, a concept applying Darwin's ideas of natural selection and survival of the fittest to human society, significantly influenced U.S. foreign policy in the late 19th century. It provided a pseudo-scientific justification for expansionism and imperialism, framing the United States' global ambitions as a natural and inevitable process. Politicians and businessmen used Social Darwinism to rationalise the American pursuit of overseas territories and markets as a manifestation of the nation's inherent superiority and destiny. This ideology underpinned many policies and actions, including aggressive trade practices and military interventions, and shaped the public's perception of America's role in the world.