Captain Robert Morrison of the Ohio Volunteer Militia marched in April 1812 with his company from Belmont County as part of Colonel Lewis Cass' 3rd Ohio Regiment.
Morrison was elected as Major of the regiment when it rendezvoused. On 9 August 1812 he volunteered to accompany Lt. Colonel James Miller's force when it marched from Detroit to fight at the Battle of Monguagon, and probably served as a volunteer Aide-de-Camp (Gilpin, 100.)
After the surrender of Detroit, as a result of which Morrison and all the officers and men of the Ohio Militia were paroled until they could be exchanged, Major Morrison returned home. He secured himself a commission as Major in the newly raised 12-month regular 27th Regiment of Infantry early in 1813, and was promoted to Lieutenant Colonel of that regiment in June.
The 27th Regiment was part of Brigadier General Lewis Cass' regular infantry brigade and served as part of the garrison of Detroit after the Battle of the Thames. The Americans suffered greatly from outbreaks of disease during the winter of 1813, and Colonel Morrison was one of the casualties, dying on 12 December 1813.