The term pre-war or prewar (antebellum) is usually applied to the most recent or significant war in a culture's history.
In the United States, Antebellum is most often used to denote the period before the American Civil War while pre-war typically refers to the period before World War II.
In real estate the term refers to buildings from the (late) 1930s in the Functionalist or Art Deco styles.