Final answer:
The Spanish-American War marked the rise of the U.S. as a global military power, showcasing its imperial aspirations and leading to the annexation of former Spanish territories, even as it imposed conditions limiting Cuba's independence.
Step-by-step explanation:
The Spanish-American War was a pivotal moment in history due to multiple reasons. Firstly, it marked the United States' emergence as a significant military power on the global stage, as it was able to seize territories and alter the balance of world power. Secondly, the war represented a critical juncture in the United States' development as an empire, showcasing its desire to expand its global reach. The primary theater of the conflict was at sea, where the U.S. Navy's victories against the Spanish fleet in the Caribbean and the Philippines crippled Spain's ability to reinforce its positions. The war concluded with Spain relinquishing control of Cuba and ceding Puerto Rico, Guam, and the Philippines to the United States. Although Cuba gained its independence, the U.S.'s imposition of the Platt Amendment ensured continued American influence over Cuban affairs, detracting from the notion of complete Cuban sovereignty.