Next engaged with his regiment during the Siege of Petersburg from July 1864 to April 1865, Rohm bugled the 16th Pennsylvania Cavalry into fighting positions during the First and Second Battles of Deep Bottom (July 27–29 and August 14–20). On August 25, 1864, he then performed the act of valor for which he would later be awarded the U.S. Medal of Honor. While serving as the chief bugler for the 16th Pennsylvania Cavalry during the Second Battle of Ream's Station, Virginia on August 25, 1864, he "remained behind to succor a wounded officer, (Colonel James Addams Beaver of the 148th Pennsylvania Infantry), who was in great danger, secured assistance, and removed the officer to a place of safety" as his regiment retreated under heavy enemy fire. Interviewed later in life about his actions that day, Rohm recalled: