Ensign Alexander Irwin is listed in Military Abstracts from Executive Minutes. Vols. 1-9 Inclusive, 1790-1817 – Sixth Battalion with Lieutenant Colonel John Culbertson, Master George Dorlan, Captain John Graham and Lieutenant Matthew Porter.
Alexander Irwin listed as Ensign in Muster and Pay Rolls of the 4th Company in Chester County, Pennsylvania under the command of James McCalmont
Private Alexander Irwin is listed in the War of 1812-1814 under the command of Captain William Steele and Ensign Thomas Underwood.
Private Alexander Irwin listed on on 8 September, 1847 in War of 1812-1814 Rolls of a company of Militia commanded by Captain William Steel of the 5th Battalion, 2nd Brigade performing a tour of duty under the command of Major McFarland who rendezvoused at New York under the General order of the Governor, Dated 26 August 1814. The Pay Rolls of a company of Militia commanded by Captain William Steel.