Rubuta ci gaba ga wannan sakin layi - Lokacin da yaki ya ɓarke da Mexico, an nada Morgan a matsayin Colonel na 2nd Ohio Volunteer Infantry. Daga bisani an ba shi izini a matsayin Colonel na 15th Infantry na Amurka a watan Maris na 1847, yana aiki a karkashin Janar Winfield Scott. Don kawo karshen yakin basasa da kisan gillar sojojin Amurka, Kanar Morgan ya kama wasu manyan 'yan Mexico kuma ya ba da sanarwar sanar da cewa ga kowane soja na Amurka da' yan tawaye suka kashe, za a kashe wani dan kasa. Nan da nan aka daina kashe-kashe. An ba shi izinin zama brigadier janar a shekara ta 1848 saboda jaruntakarsa a yakin Contreras da Churubusco.
, inda ya ji rauni mai tsanani. Da ya koma Ohio don murmurewa, ya sami godiya ta hukuma daga majalisa ta Ohio.