born at cumberland house, in the hudson's bay company territories, mackenzie was the son of jane and roderick mackenzie. his father, a cousin of the explorer sir alexander mackenzie, was an agent of the company. he was educated at upper canada college, toronto, the high school of montreal, the st. francis college at richmond, and mcgill university at montreal, then articled in montreal to melbourne tait and john joseph caldwell abbott, the second of whom later became prime minister of canada.