"Some 2,000 hidden infections were already spreading through major cities"

From the New York Times, comes a great read showing research on how much travel (without social distancing and other measures) spread the virus around  before the country acted on it. 

Note: this is best viewed on a laptop/desktop. The phone screen was too small to display the scrolling data.
 

"Invisible outbreaks sprang up everywhere. The United States ignored the warning signs. We analyzed travel patterns, hidden infections and genetic data to show how the epidemic spun out of control."

https://www.nytimes.com/interactive/2020/us/coronavirus-spread.html

screen capture of NY Times article