In late 2019 the Chinese city of Wuhan reported several cases of what doctors thought was pneumonia. But it wasn't long before officials identified a new coronavirus behind the outbreak: SARS-CoV-2. COVID-19, the respiratory illness caused by the virus, quickly spread through China and then around the world. In the United States and everywhere else it landed, the virus drastically changed familiar ways of life. Events were canceled, schools moved online, and whole countries shut down in an attempt to slow the virus's spread. Meanwhile, frontline workers kept essential services running, and scientists raced to discover as much as they could about the viral threat. Follow the timeline of the COVID-19 pandemic, learn about key figures in the US government's response, and find out what's next in the fight against the coronavirus.