The detonation of the bombs thrown at the emperor’s carriage in Paris on January 14, 1858, resonated across the Atlantic world. A group of Italian nationalists led by Felice Orsini ventured an assassination attempt on Napoleon III, whom they regarded as a symbol of Europe’s anti-liberal establishment. Orsini failed and was sentenced to the guillotine. His death on the scaffold of French monarchy stirred observers on both sides of the Atlantic. While some hailed Orsini as a martyr for universal freedom, others saw in him an ominous herald of bloodshed and terror. This article describes how public interest in the attempt on Louis Napoleon’s life transcended geographical boundaries and focuses on the ways in which Orsini’s radical legacy stoked social and political conflict in the antebellum United States. It dissects the hostile responses of northern conservatives and southern slaveholders but also shows how the executed Italian patriot became a common rallying point for white abolitionists, black activists, and European refugees of the 1848 revolutions. In locating Orsini in the stream of images and agents of European and American upheaval that connected both continents in a period of massive migration and revolutionary unrest, the article builds on a growing body of scholarship that examines the coming of the Civil War in a transnational framework. Ultimately, it argues that the representation of foreign violence was essential for midcentury Americans struggling to define what made them distinct as a nation, but also what tied them to the greater community of human beings.