Some years—1789, 1929, 1989—change the world suddenly. Or do they? In 2020, a pandemic converged with an economic collapse, inequalities exploded, and institutions weakened. Yet these crises sprang not from new risks but from known dangers. The world—like many patients—met 2020 with a host of preexisting conditions, which together tilted the odds toward disaster. Perhaps 2020 wasn’t the year the world changed; perhaps it was simply the moment the world finally understood its deadly diagnos...

In July 1919, an explosive race riot forever changed Chicago. For years, black southerners had been leaving the South as part of the Great Migration. Their arrival in Chicago drew the ire and scorn of many local whites, including members of the city’s political leadership and police department, who generally sympathized with white Chicagoans and viewed black migrants as a problem population. During Chicago’s Red Summer riot, patterns of extraordinary brutality, negligence, and discriminato...