If all Canadian Prime Ministers are listed alphabetically, who would be last?
A: John Turner
Sir John Abbott would be first (he succeeded Macdonald after Sir John A. passed away in 1891)
Who was the last Canadian Prime Minister who didn’t have a spouse while in office?
A: Kim Campbell
She was divorced (for the second time) before becoming Prime Minister. 
Pierre Trudeau had no spouse for the final two months he was in office (though he was separated from Margaret in 1977, their divorce wasn’t final until 1984). W.L. Mackenzie King (never married) and Mackenzie Bowell (widower) were the only other PM’s without a spouse.