On this day in 1920, the Department of Justice launched a series of attacks against leftists and labor organizers across more than 23 states, arresting more than 3,000. President Hoover later admitted that there were "clear cases of brutality".

Antonie Pannekoek, born on this day in 1873, was a Dutch astronomer, philosopher, socialist revolutionary, and Marxist theorist associated with council communism. "Common ownership by the producers can be the only goal of the working class."