Select the war the United States was NOT involved in.

The Crimean War is the correct choice because the United States did not participate in this conflict. The crime occurred between 1853 and 1856 and primarily involved Russia against an alliance of the Ottoman Empire, France, Britain, and Sardinia. Although the United States was a nation at this time, its foreign policy was focused on its own domestic issues and expansion rather than involvement in European conflicts.

In contrast, the Civil War, World War I, and World War II were significant events in which the United States played a crucial role. The Civil War was a pivotal internal conflict from 1861 to 1865 concerning issues like slavery and states' rights. The U.S. participated in World War I from 1917 to 1918, joining the Allies against the Central Powers. Similarly, during World War II, from 1941 to 1945, the U.S. was actively involved in a global conflict against the Axis Powers, significantly impacting the war's outcome.

Thus, the lack of U.S. involvement in the Crimean War distinguishes it from the other wars listed.