Mackay was born in 1864 and was educated at Mount Gambier Grammar School but left at age 13.

[10] At one time, Mackay had also acquired Balmoral Station from James Munro; he later sold it to B. H. Sharpe and Company.

[11] Mackay left Western Australia in 1905 and returned to Victoria while retaining his pastoral interests.

He bought Melville Park where he lived until 1912, then moved to St Kilda and eventually to Rock House Estate near Kyneton, where he hoped to establish a horse stud.

[14] He was buried at Brighton Cemetery three days later with several prominent members of the racing community acting as pall-bearers.