Isabella Macdonald, née Clark (1811 – 1857) was the first wife of John A. Macdonald

John A. Macdonald

Sir John Alexander Macdonald, GCB, KCMG, PC, PC , QC was the first Prime Minister of Canada. The dominant figure of Canadian Confederation, his political career spanned almost half a century...

, the premier of the Province of Canada

Province of Canada

The Province of Canada, United Province of Canada, or the United Canadas was a British colony in North America from 1841 to 1867. Its formation reflected recommendations made by John Lambton, 1st Earl of Durham in the Report on the Affairs of British North America following the Rebellions of...

 in 1856. She was Macdonald's first cousin.

She became ill after just two years of marriage, and died in 1857. Medical examinations concluded that she was suffering from a somatization

Somatization

Somatization is currently defined as "a tendency to experience and communicate somatic distress in response to psychosocial stress and to seek medical help for it".This can be, but not always, related to a psychological condition:...

 disease. She had also developed an addiction

Substance use disorder

Substance use disorders include substance abuse and substance dependence. In DSM-IV, the conditions are formally diagnosed as one or the other, but it has been proposed that DSM-5 combine the two into a single condition called "Substance-use disorder"....

 to opium

Opium

Opium is the dried latex obtained from the opium poppy . Opium contains up to 12% morphine, an alkaloid, which is frequently processed chemically to produce heroin for the illegal drug trade. The latex also includes codeine and non-narcotic alkaloids such as papaverine, thebaine and noscapine...

 mixed with wine

Wine

Wine is an alcoholic beverage, made of fermented fruit juice, usually from grapes. The natural chemical balance of grapes lets them ferment without the addition of sugars, acids, enzymes, or other nutrients. Grape wine is produced by fermenting crushed grapes using various types of yeast. Yeast...

.

After Clark's death, Macdonald went on to become the first post-Confederation Prime Minister of Canada

Prime Minister of Canada

The Prime Minister of Canada is the primary minister of the Crown, chairman of the Cabinet, and thus head of government for Canada, charged with advising the Canadian monarch or viceroy on the exercise of the executive powers vested in them by the constitution...

. He remarried to Susan Agnes Bernard in 1867, five months before Canadian Confederation.

Macdonald and Clark had two sons: John and Hugh

Hugh John Macdonald

Sir Hugh John Macdonald, PC was the only surviving son of the first Prime Minister of Canada, Sir John A. Macdonald, and was a politician in his own right, serving as a member of the Canadian House of Commons and a federal cabinet minister, and briefly as the eighth Premier of Manitoba.-Early...

; the former died at 13 months.