devin obtained a commission in the regular army after the civil war under the provisions of the army act of 1866. this act required that the officer ranks of the new infantry and cavalry regiments be filled by a certain percentage of officers from the volunteer regiments raised during the civil war. ending the war as a brigadier general and brevet major general, devin became a lieutenant colonel and was assigned to the 8th u.s. cavalry. initially serving with part of the regiment in new mexico, devin assumed command of the subdistrict of prescott in arizona in late 1867. he died of stomach cancer and exposure, on sick leave from active duty, as colonel of the 3rd u.s. cavalry. devin was initially interred in calvary cemetery on long island, but upon his wife's death in 1897, both were interred in west point cemetery, west point, new york, very near his old friend and commander john buford.