He served in the Legislative Assembly of New Brunswick as member of the Progressive Conservative party,[1][2] which he led from 1939 to 1951.

He attended the Rothesay Collegiate School, later going to McGill University.

[4] Mackay ran for the Progressive-Conservative nomination for the Premier of New Brunswick during the 1944 elections, losing to Liberal leader John B.

[4] Hazen herself also participated in Conservative politics, at one point serving as president of the National PC Women's Association.

Mackay's health had been declining in the months leading up to his death and he went to Boston to seek medical help.