Name one war fought by the U.S. in the 1900s.

World War I is indeed one of the notable wars fought by the United States in the 1900s. The U.S. entered the war in 1917, joining Allied Powers against the Central Powers, including Germany and Austria-Hungary. This conflict was a significant global event that challenged the United States' stance as an emerging power and brought about profound changes in military and foreign policy.

In contrast, the other wars listed occurred in earlier centuries. The American Revolution, which took place from 1775 to 1783, was the thirteen American colonies' struggle for independence from British rule. The Civil War, fought from 1861 to 1865, was a crucial internal conflict addressing issues such as slavery and states' rights. The War of 1812 occurred between 1812 and 1815 and involved conflict with Britain over maritime rights and territorial expansion. Each of these events played a vital role in shaping U.S. history, but they do not fit the timeline specified in the question, which focuses on the 1900s.