He was the son of Andrew McElvaine JP and Susan McElvaine. In 1901 the family lived in house 14, Lisnabrague, Scarva, Co. Down. By 1911 the property was known as house 7, Lisnabraque, Scarva, Co. Down.
The family also lived at Union Lodge, Poyntzpass.
His father, Andrew died on 5th January 1914.
McElvaine enlisted into the Royal Naval Air Service (RNAS) as an Armoured Car Driver. His Service Number (RNAS) was F2889.
He later served with the Royal Irish Fusiliers. On 8th January 1916, he attained the rank of Temporary 2nd Lieutenant. Transferred to HB MGC on 16th December 1916 ('D' Battalion).
He was wounded on 5th May 1917. Later he was treated for treated trench fever at Poperinge and returned home.
The Belfast News Letter of 17th May 1917 reports:
The Belfast Banking Company 'Roll of Honour' booklet records McElvaine as 'previously wounded'.
The London Gazette dated 23rd April 1920 records two entries:
Temp. Lt. A. F. McElvaine relinquishing the Acting rank of Capt. on ceasing to be employed as (an) Instructor - 1st October 1919.
Temp. Lt. A. F. McElvaine relinquishes his commission on completion of service, 4th January 1920, and is granted the rank of Captain.
It is not known if Andrew returned to the Belfast Banking Company. However, from the following evidence, he may have joined a London based bank and continued his career in London, Argentina and Spain.
There are various records on Ancestry.Co.UK of an A F McElvaine departing and returning to the UK from Argentina.
On 15th August 1935, an A F McElvaine (40) arrived in London from La Plata, Argentina with Hazel (Knapp) Denis McElvaine (24) and Denis Philip McElvaine (1). AFM is described as a bank employee with an address at 6-8 Tokenhouse Yard, London.
On 18th November 1950, an A F McElvaine departed London for Argentina. Described as a bank clerk with an address at 25 Fifth Avenue, Baylands, Bangor.
On 25th February 1984, an A F McElvaine died in Malaga, Spain leaving the sum of £26,188 (probate, London, 4th December 1984.