This report represents Volume I of the All-domain Anomaly Resolution Office's (AARO) Historical Record Report (HR2) which reviews the record of the United States Government (USG) pertaining to unidentified anomalous phenomena (UAP). In completing this report, AARO reviewed all official USG investigatory efforts since 1945, researched classified and unclassified archives, conducted approximately 30 interviews, and partnered with Intelligence Community...