In recent years, far-right terrorism has become a leading national security concern for the United States. However, this type of violence and the extremism that inspires it are far from new. The U.S. far right has been gaining momentum for decades, helping to proliferate a web of conspiracy theories and insidious ideologies such as white supremacism, antisemitism, and anti-government extremism, all of which are converging to pose a grave threat to American democracy.