A key moment in the pardon power came after the civil war, when president Andrew Johnson issued “a full pardon and amnesty” to any person “who, directly or indirectly, participated in the late insurrection or rebellion” during the civil war. This and similar pardons around the same time led the US supreme court to interpret the pardon power to allow the president to grant broad amnesty to a group of people and not just for specific crimes already committed, Meyler said.