[2] He was involved in the procurement of pieces to display in the gallery and also launched a competition to determine the design of the building.

[1] Mackay stood as an independent in the Wanganui electorate in the 1908 election, but was defeated by James Thomas Hogan and George Hutchison in the first ballot.

[3] Mackay met Walter D'Arcy Cresswell in 1920 whilst still holding the position of Mayor of Wanganui.

[4] It was alleged that Mackay made advances on Cresswell, who responded by threatening to publicly expose his homosexuality.

[1] Newspapers at the time indicated that many people found Mackay's release unfair, and speculated that he was given leniency due to his political past.

[5] In his latter function he reported on the communist street riots of May Day 1929, where he was fatally shot by a police officer who had mistaken him for a rioter.

In the 1980s, efforts were made by LGBT activists to have Mackay's name placed back into the Sarjeant Gallery foundation stone.