Who was the leader of the Liberal Party during the Great Depression?

The leader of the Liberal Party during the Great Depression was William Lyon Mackenzie King. He served as Prime Minister of Canada during the initial years of the Great Depression, which began in 1929. King's approach to the economic crisis included advocating for federal intervention in the economy and emphasizing the importance of social welfare programs to address the challenges faced by Canadians. He was in office during a critical time when many people were suffering from unemployment and economic hardship, and his policies aimed to provide relief and support for those affected.

In contrast, R.B. Bennett was the leader of the Conservative Party and served as Prime Minister during a portion of the Great Depression, introducing measures such as the New Deal in Canada. John A. Macdonald was not directly involved during this period, having passed away in 1891, and Wilfrid Laurier, who was Prime Minister before King, governed from 1896 to 1911. Therefore, the context of leadership and the timing of their respective tenures clearly identifies Mackenzie King as the correct answer in relation to the Great Depression.