Francis Scott Key, the pro-slavery lawyer and amateur poet who penned “The Star-Spangled Banner” after witnessing the British bombardment of Fort McHenry 200 years ago, was famously inspired by the resilient spirit of a young nation. Forty-five years later, Key’s other notable creation, his only son Philip Barton Key II, would experience an entirely different side of American life when he was slain in 1859 by a U.S. congressman and disgruntled cuckold named Daniel Sickles.