[2] MacDonald was born in Cranbrook, British Columbia, and moved with his family to Tullochgorum, Quebec in 1923 and then earned a bachelor's and master's degree from Queen's University.

He was a candidate in the August 1953 federal election for the British Columbia riding of Kootenay East, and finished a strong third against Liberal Jim Byrne with 28% of the vote.

[3] As the province's population became more urban and as social issues came to the forefront of political discussion, the NDP had a major breakthrough in the 1967 election rising from seven seats to 20.

[3] This new success led to increasing pressure for new leadership, as the party was seen as a potential victor and many activists felt a younger leader was needed to catch the mood of the times.

At the leadership convention that fall, Stephen Lewis defeated Walter Pitman and succeeded MacDonald as Ontario NDP leader.

[2] The Progressive Conservative government was able to rally business support by depicting Lewis as dangerously left-wing, and the NDP did not gain seats in the 1971 election.

[4] The 1960s youth-quake was moving into federal politics, and a group of New Left academics and activists called The Waffle presented the fiercest opposition to MacDonald and other "establishment" members.

[4] With the help of the union delegations, and the party's establishment, MacDonald was victorious on April 23, 1971 and became the president during the same convention that saw Tommy Douglas pass the leadership torch on to David Lewis.

[4] MacDonald supported Ian Deans's unsuccessful bid to replace Lewis as party leader in 1978, and helped to draft Bob Rae for the leadership in 1982.

[2] MacDonald's autobiography, Happy Warrior: Political Memoirs, was published in 1988 and the second edition in 1998, to add the Rae years as the first NDP Ontario government.

In 2004, MacDonald supported a young NDP Provincial Executive member named Paul Ferreira in his campaign to be the area's MPP.