In an increasingly antiracist era when problematic iconography — ranging from Aunt Jemima and Uncle Ben to even the Dukes of Hazzard General Lee car and country band Lady Antebellum’s name — is being reassessed, revised or retired, America’s national anthem, “The Star-Spangled Banner,” seems to be striking a wrong note. Last week, protesters in San Francisco toppled a statue of the song’s composer, Francis Scott Key, a known slaveholder who once said that African-Americans were “a distinct and inferior race of people, which all experience proves to be the greatest evil that afflicts a community.” This week, Liana Morales,...