Born in 1812 in Glengarry County, Upper Canada, John Sandfield was the first of five children for Alexander and Nancy Macdonald, who were Roman Catholic Highland Scots.

[1] Leaving school at 16, he became a clerk at several general stores, before deciding to enter the legal profession, eventually articling under Archibald McLean.

When McLean was later elevated to the Court of King's Bench for Upper Canada, Macdonald became his assistant, which allowed him to meet Allan MacNab, Thomas Talbot and William Henry Draper (with whom he would resume his articling).

[citation needed] Macdonald was later appointed as Queen's messenger, charged with carrying dispatches between the Lieutenant-Governor of Upper Canada and the British Minister in Washington.

[citation needed] In 1841, Macdonald was approached by two local conservative political figures, Alexander Fraser and John McGillivray, to stand for election for the Glengarry riding in the new Legislative Assembly of the Province of Canada.

However, Macdonald at this point did not have firm political views, and once in Parliament, he gradually shifted towards the Reform group and away from Draper.

[4] A Reformer and advocate of responsible government, Macdonald served in all eight Assemblies of the Province of Canada prior to Confederation.

This group joined with the Clear Grits to form the opposition Liberal Party led by Edward Blake and Oliver Mowat.

In the early years of confederation, politicians were allowed to serve simultaneously in the House of Commons and in a provincial legislature.

Nineteenth century religious tensions aside, Macdonald's election as Ontario's first Premier makes his Catholicity an important historic symbol.