Second American Revolution is the event in the Wolfenstein II: The New Colossus that involves BJ and the entire American Resistance network to rise up against the Nazis to liberate the American Territories from their oppressive rule.
After the Nazis had conquered the United States by dropping an atom bomb on New York City, the United States surrendered and the Government pleaded with the American citizens and the Armed Forces to step down from fighting and cooperate with the Nazi regime. However, the order to surrender fell unto deaf ears for some Americans such as Grace Walker, Horton Boone, Joseph Stallion's father as well as remnant of U.S. military personnel like Captain Gerald Wilkins, causing huge trouble for the Nazi regime to pacify the American Territories. Their resistance was eventually crushed by the arrival of the Ausmerzer, causing the entire American Resistance network to scatter across the country. As a result, the Nazis managed to pacify the American Territories and marked the event as Liberation Day.
The arrival of B.J. and the Kreisau Circle changed the tide of the war in the favor of the American Resistance Network as B.J. managed to destroy the Oberkommando headquarters in Roswell with a nuclear warhead and managed to get to Horton Boone to rally the American Resistance together to fight against the occupying Nazis and their collaberators.
After the capture of the Ausmerzer, B.J. and his group assassinated Irene Engel live on the Jimmy Carver show in with Grace Walker (or Probst Wyatt III, depends on timeline) declaring their uprising to the rest of the American Territories making the Second American Revolution a reality as hundreds of uprisings erupted across America as the grip of the Nazi regime crumbles. Furthermore, B.J.’s assassinations of all 16 Übercommanders caused the total collapse of the chain of commands of Nazi forces in the territories. As a result of these events and the quick gains by the American Resistance, the puppet government collapsed and the American people soon liberated the country from Nazi rule ending their oppressive occupation after 12 years.