Kammala wannan jumla: Lokacin da yaki ya barke da Mexico, an nada Morgan Kanal 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 1848 don ƙarfinsa a yakin Contreras da
Churubusco, inda aka yi masa mummunan rauni. Da ya koma Ohio don murmurewa, ya sami godiya ta hukuma daga majalisa ta Ohio.