What is the name of the US war which was fought between the North and the South?

The name of the war fought between the North and the South in the United States is the Civil War. This conflict, which lasted from 1861 to 1865, arose primarily from tensions surrounding issues of slavery and states' rights. The Northern states, known as the Union, opposed the expansion of slavery into the territories and sought to maintain the integrity of the nation. In contrast, the Southern states, forming the Confederacy, aimed to preserve their way of life, which was deeply intertwined with the institution of slavery.

The Civil War was a pivotal moment in U.S. history, leading to significant social, political, and economic changes. Its primary outcome was the preservation of the Union and the abolition of slavery, with the passage of the 13th Amendment. This distinguishes it clearly from other wars mentioned, such as the Revolutionary War, which involved the colonies' fight for independence from British rule, the War of 1812, which was primarily about maritime rights and territorial expansion, and the Spanish-American War, which centered on imperial and expansionist conflicts. Each of these wars had unique causes and consequences, making the Civil War distinctive in its focus on issues of unity and civil rights.