For several years, PBS Frontline has collaborated with ProPublica to investigate the rise of extremism in the United States. In the aftermath of the January 6th riot at the Capitol building, Frontline, ProPublica and Berkeley Journalism's Investigative Reporting Program teamed up to examine how far-right extremist groups had evolved in the wake of the deadly 2017 Charlottesville rally. American Insurrection is a report that draws on this extensive background to examine the latest developments and pose questions about where these extremist movements may be headed.