Names of the American Civil War

The most common name for the American Civil War in modern American usage is simply "The Civil War". Although rarely used during the war, the term "War Between the States" became widespread afterward in the Southern United States. During and immediately after the war, Northern historians often used the terms "War of the Rebellion" or "The Great Rebellion", and the Confederate term was "War for Southern Independence", which regained some currency in the 20th century but has since fallen out of use. The name "Slaveholders' Rebellion" was used by Frederick Douglass and appeared in newspaper articles during that era. "Freedom War" is used to celebrate the war's effect of ending slavery in the United States.

During the Jim Crow era of the 1950s, the term "War of Northern Aggression" developed under the Lost Cause of the Confederacy movement by Southern historical revisionists or negationists. This label was coined by segregationists in an effort to equate contemporary efforts to end segregation with 19th-century efforts to abolish slavery.

Several names also exist for the forces on each side. The Union practice was to name their armies for the river valleys where they initially operated, while the Confederacy generally used state names. For example, the Army of the Tennessee was a Union army named for the river, while the Army of Tennessee was a Confederate army, named for the state.