As COVID-19 spread through the United States different states and different counties enacted social distancing policies at different points in time. NYT used data from cell phones (similar to the Social Distancing Scoreboard posted earlier) to look at the impact of these policies and the amount of movement. This can be used to see the effects of social distancing policies and the number of people who followed them on the spread of the virus through out the United States.
https://www.nytimes.com/interactive/2020/04/02/us/coronavirus-social-distancing.html