Before Covid-19, American cities were on an upswing. More and more people were flocking to enjoy trendy, car-free lifestyles near revitalized downtowns. But in a matter of weeks, the pandemic reversed that equation and the density that once made cities seem vibrant now made them dangerous.

Many city dwellers with the means to flee to less-dense areas did. Downtowns that once hummed with office workers by day and restaurant and club patrons by night were now largely empty and the businesses that catered to those clienteles shuttered, often permanently. The pandemic has altered the landscape of America’s cities, and ongoing disruptions to tourism, business travel, retail stores and office work mean that cities need to reboot their business models. Meanwhile, Americans are rethinking why they live where they live, including whether they want to continue to live in cities at all — sometimes spurred by pandemic-related surges in crime and homelessness.

In this issue of Recovery Lab: Cities, we explore the challenges the pandemic has brought to American cities. In our centerpiece story, freelance writer Eric Sciglianoreports on how the untethering of work from home has unleashed what some have called Covid’s “great dispersion” — a geographical resorting in which some cities gained population, some lost it and some are still in flux. The upshot will change America’s communities for years to come, and may even have long-lasting impacts on our society and politics.