Among the cornucopia of work on view at the Art Institute of Chicago for its ongoing exhibition The New Contemporary is, above: Andy Warhol. “Twelve Jackies,” 1964. The Art Institute of Chicago, Gift of Edlis/Neeson Collection. © 2015 The Andy Warhol Foundation for the Visual Arts, Inc./Artists Rights Society (ARS), New York. John F. Kennedy was assassinated 55 years ago Thursday, revealing a nation’s dark soul — and a First Lady’s courage to help it see some light.