"Antebellum" means "before the war," but it wasn't widely associated with the U.S. Civil War (1861-1865) until after that conflict was over. The word comes from the Latin phrase "ante bellum" (literally, "before the war"), and its earliest known print appearance in English dates back to the 1840s.
Rational ignorance suggests that a. voters are ignorant on issues that are not of special interest to them b. voters do not pursue information about issues before voting c. low voter turnout is due to a lack of understanding of the platforms of each political party d. voters are uninterested in the electoral process