William Lyon Mackenzie King's enduring political legacy as Canada's longest-serving Prime Minister can be attributed to his ability to balance visionary leadership with political pragmatism. Through a nuanced understanding of Canada's complexity and its historical cleavages, King crafted his vision to align with the nation's readiness for change, while strategically avoiding actions that might threaten national unity. This study delves into King's intricate decision-making process, analyzing key moments throughout his political career, and culminating in the cancelled 1948 trade deal with the United States. By examining King's speeches, diaries, and policies, this research highlights how he carefully and meticulously pursued his vision for Canada. Such an appraisal of King’s leadership challenges the depiction of King by academics as indecisive and acting only to maintain political power. Moreover, this thesis argues that King's deliberate actions and inaction during critical junctures, such as during the conscription crisis during the Second World War and various policies to address both national and international circumstances while he was Prime Minister, demonstrates his leadership skills. In short, this thesis sheds light on the nuanced interplay between King's political maneuvering and his steadfast commitment to a vision for Canada that privileged national unity primarily while moving Canada in a direction that he believed best for the nation and for Canadians.