Alexander  McDonaldwas a 21 year old orphan and he enlisted on October 9, 1917. His address was Gembrook - C/o Mr Pitt, Farmer, Gembrook. He had no next of kin on enlistment but that was later changed to Charlotte Buchanan of Gembrook, whom he listed as his aunt.

He was sent to Broadmeadows Camp for training and attached to the 2nd Depot Battalion from 28 November 1917 to 17 December. From there, along with the other recruits, he embarked 28 February 1918 on the A71 H.M.A.T. Nestor , Landing at Liverpool on 20 April 1918. The new recruits marched out to camp at Codford and were placed in the 12th Training Battalion. On 8 July, they marched in to Folkestone to board a ship for France, then marched out to the battlefront, where Alexander McDonald was taken on strength with the 46th Battalion. 

On 25th August he was wounded in action, gassed. He was sent back to England and admitted to the Beaufort War Hospital. He was finally discharged on 30 January, 1919, declared medically unfit, and sailed back to Australia, disembarking on 12 December, 1919.

Research by the Casey Cardinia Commemorate Committee reveals more information:

 There is a form in Alexander McDonald's file from the 'Office of the Victorian Government Statist' and it stated that  a search had been done of the Indexes and there was no record  of  a birth of a Alexander McDonald in Victoria between the years 1895 and 1899. However, there is a birth of an Alexander McDonald Buchanan to a Charlotte Buchanan (father listed as unknown) in 1896. I believe that this is our Alexander and that his 'aunt' Charlotte was really his mother. Did he know this then or later?  That would be interesting to know. I guess the best thing about this is that Charlotte had the opportunity to have contact with her son. Most unmarried mothers at the time would have had the baby taken from them and given up for adoption.

Alexander McDonald died on 30 October, 1872. There is a plaque remembering him in the Victorian Garden of Remembrance at Springvale.  A check of birth records confirms Charlotte Buchanan as his mother. The space for father simply says Buchanan.