War Between The States.
Not "civil war"
The Congress of the United States used the term, "War Between the States" in two measures enacted into law; one measure became Public Law 834 in 1950, and a Resolution, H.580 was adopted by the House in 1944. The term "War Between the States" has been used in various reports on bills during the 70th, 71st, 72nd, 74th, 80th and 81st Congresses.