Which war was fought by the United States in the 1800s?

The War of 1812 was a conflict fought between the United States and Great Britain, occurring from 1812 to 1815. This war arose from a variety of factors, including trade restrictions imposed by Britain, the impressment of American sailors into the British Navy, and the desire for expansion into British-held territories in North America. It is significant in American history as it helped to foster a sense of national identity and patriotism, even though it ended without a clear victor.

In contrast, the other wars listed occurred in different time periods. World War I took place from 1914 to 1918, while the Cold War was a prolonged period of tension between the United States and the Soviet Union that lasted roughly from the end of World War II until the early 1990s. The War on Terror is a relatively modern conflict that began after the September 11 attacks in 2001 and continues today. Thus, the War of 1812 is uniquely positioned as the war fought by the United States in the 1800s.