Which U.S. war is known for ending slavery?

The U.S. war known for ending slavery is the Civil War. This conflict, which took place from 1861 to 1865, was primarily fought over the issues of slavery and states' rights. The war concluded with the defeat of the Confederate states, which had seceded from the Union primarily to preserve the institution of slavery.

The Civil War led to significant legal and constitutional changes, notably with the passage of the 13th Amendment in 1865, which formally abolished slavery in the United States. This amendment made it illegal to hold individuals as slaves, effectively ending centuries of legal slavery in the country.

The other conflicts mentioned, such as the Mexican-American War, World War II, and the War of 1812, did not have the abolition of slavery as a central focus or outcome. The Mexican-American War primarily involved territorial disputes, World War II was largely about global conflict and fascism, and the War of 1812 centered around issues like trade restrictions and territorial expansion. Therefore, none of these wars significantly influenced or contributed to the end of slavery in the United States as the Civil War did.