The American Civil War has been known by a number of names since it began in 1861. These names reflect the historical, political, and cultural sensitivities of different groups and regions.
The most common name in modern American usage is simply the "Civil War". Although used rarely during the war, the term "War Between the States" became widespread afterward in the Southern United States. During and immediately after the war, historians often used the term "War of the Rebellion" or the "Great Rebellion", while the Confederate term was "War for Southern Independence". The latter regained some currency in the late 20th century, but has again fallen out of use. Other terms often reflect a more partisan view of events, such as the "War of Northern Aggression" or the "War of Southern Aggression". The "Freedom War" is used to celebrate the effect the war had on ending slavery. In several European languages, the war is called "War of Secession". In most East Asian languages, the war is called "Battle between North and South side of the United States" or more commonly as "American (US) North-South War", depending of their languages.
A variety of names also exist for the forces on each side; the opposing forces named battles differently as well. The Union forces frequently named battles for bodies of water that were prominent on or near the battlefield; Confederates most often used the name of the nearest town. As a result, many battles have two or more names that have had varying use, although with some notable exceptions, one has tended to take precedence over time.
In the United States, "Civil War" is the most common term for the conflict; it has been used by the overwhelming majority of reference books, scholarly journals, dictionaries, encyclopedias, popular histories, and mass media in the United States since the early 20th century. The National Park Service, the government organization entrusted by the United States Congress to preserve the battlefields of the war, uses this term. Writings of prominent men such as Jefferson Davis, Robert E. Lee,Ulysses S. Grant, William Tecumseh Sherman, P.G.T. Beauregard, Nathan Bedford Forrest, and Judah P. Benjamin used the term "Civil War" during the conflict.Abraham Lincoln used it on multiple occasions. In 1862, the United States Supreme Court used the terms "the present civil war between the United States and the so called Confederate States", as well as "the civil war such as that now waged between the Northern and Southern States".