In 1793, a yellow fever outbreak prompted a fraught discussion about race. Here is what happened next. "I first read about these 18th-century nurses when I was quarantined in my own flat in Philadelphia, a short distance from the city’s hospitals. Two centuries on, the disease has changed but the story hasn’t. Now, as then, a disproportionate share of the city’s essential workers are black and poor — the nurses, technicians and delivery drivers who keep the city running while many of us stay in our homes. Now, as then, these men and women have been hit hardest by a contagious virus: the rate of recorded COVID-19 cases is almost twice as high among black Philadelphians as among white ones, according to local-government data." Edward Posnett reflects on The Economist's 1843 magazine.