evidence: The trend we identify represents a substantial deviation from patterns preceding the pandemic. Before COVID-19, incarcerated Black people accounted for a declining share of the total prison population: roughly 41.6% of people incarcerated in state prisons were Black in March 2013, and by March 2020 this number had fallen to 38.9%—a decline of 2.7 percentage points over seven years. During the height of COVID-19 closures, from March 2020 to November 2020, this percentage increased by 0.9 points, erasing much of the progress over the last decade (Figs. 1b and 2 and Supplementary Fig. 2; see Supplementary Fig. 16 for comparison between effects among non-white versus Black populations). The trend we observe at the national level is reproduced exactly among states with the highest Black and Latino populations, and persists in some form in nearly every other state. [...] a, Percentage of incarcerated population who are Black and white. Note especially that the effect size of the demographic changes during the COVID-19 pandemic are more pronounced in the incarcerated Black population (see Supplementary Fig. 16 for additional comparisons). b, Percentage of incarcerated Latino people. c, Percentage of white, Black and Latino incarcerated populations, normalized by the average value between March 2019 and February 2020. d, Percentage of white, Black and Latino incarcerated populations, normalized by the slope of each curve between March 2019 and February 2020.