The Spanish-American War helped the United States become a strong leader in the Americas by expanding its territory and asserting its influence through policies like the Monroe Doctrine. The war resulted in significant territorial gains for the U.S. and marked its emergence as a global power. Therefore, the correct answer is A.
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The Spanish-American War significantly established the United States as a dominant power in the Americas, marking its emergence into a leadership role in the region. Following the war, the U.S. adopted policies like the Monroe Doctrine more aggressively to prevent European expansion. Therefore, the war helped the U.S. become a strong leader in the Americas. ;