This study quantifies the relationship between school closure timing and COVID-19 deaths and cases in the general population in all U.S. states. COVID-19 has higher symptomatic infection rates among the elderly, suggesting school closures could be unrelated to transmission. However, predicting daily cumulative COVID-19 deaths by state, earlier school closure is related to fewer deaths per capita and slower growth in deaths per capita. Results are similar for COVID-19 cases per capita.