Which war directly followed the War of 1812?

The war that directly followed the War of 1812 is the Mexican-American War. The War of 1812, which lasted from 1812 to 1815, was primarily a conflict between the United States and Great Britain, largely over maritime issues and territorial expansion. After the War of 1812, tensions and disputes over land and borders continued, particularly concerning Texas, which had declared its independence from Mexico in 1836.

The Mexican-American War occurred from 1846 to 1848 and was driven by the U.S. annexation of Texas and the desire for further territorial expansion into Mexican lands, leading to a significant shift in the U.S. borders. This war resulted in the U.S. gaining vast territories, including present-day California, Arizona, New Mexico, Nevada, Utah, and parts of Colorado and Wyoming.

The other options, such as the Civil War, Spanish-American War, and World War I, occurred much later and are not directly related to the period immediately following the War of 1812. Therefore, the Mexican-American War is accurately identified as the conflict that directly followed.