The headline: The map illustrates the changing picture of COVID-19 from March 1st to August 13th, 2020. The height of each bar is proportional to the total weekly cases and the color is related to the weekly case rate (cases per million population; blue=low, yellow=moderate, red=high). The color legend is the same as the post
https://chartedterritory.us/2020/07/14/animating-coronavirus-the-spread-of-covid-19-in-the-united-states-07-12-2020/. Each grid cell is 50 x 50 km and is the population-weighted-average of county-level COVID data. The static map (above) shows the situation on August 1st, 2020.
The data: COVID-19 data were collected from USAFacts (https://usafacts.org/visualizations/coronavirus-covid-19-spread-map/).