Alexander Irwin listed as Ensign, 4th Company under command of Captain James McCalmont in Pennsylvania Archives, Colonial Records, Series 6, Volume IV, Military Abstracts from Executive Minutes. Vols. 1-9 Inclusive. 1790-1817 page 228.
Private Alexander Irwin is listed in the War of 1812-1814 in Third Division, Infantry detached from the 47th Regiment under command of Captain William Steele.
Private Alexander Irwin is listed in the War of 1812-1814 in Miscellaneous Rolls, Fifteenth Division - The Return of the First Rifle Company detached to the 125th Regiment who Volunteered their service under the command of Captain James Scott