What major influence drove the expansion of the U.S. Navy in the late 19th century?

The major influence driving the expansion of the U.S. Navy in the late 19th century was indeed the closure of the land frontier. This period marked significant changes for the United States, as the country transitioned from a primarily land-based focus to one that emphasized maritime power. With the frontier largely settled and fewer opportunities for territorial expansion within North America, American leaders began to see the oceans as a new frontier for expansion and influence.

The closing of the land frontier sparked interest in building a formidable naval presence to protect American interests overseas, facilitate trade, and project power. This aligned with the broader trends of imperialism during that era, as the U.S. looked to acquire territories and assert its influence globally, illustrated by actions like the annexation of Hawaii and the involvement in the Spanish-American War.

By expanding the Navy, the United States aimed to secure sea lanes for commerce, protect its growing economic interests abroad, and assert its status as an emerging global power. The push for a stronger navy by figures like Admiral Alfred Thayer Mahan further reinforced this direction, advocating the strategic importance of sea power in national greatness.