From Franklin Roosevelt's final days through Harry Truman's extraordinary transformation, this is the enthralling story behind the most consequential presidential transition in US history.

When Roosevelt, in failing health, decided to run for a fourth term, he gave in to the big city Democratic bosses and reluctantly picked Senator Truman as his vice president, a man he barely knew. Upon FDR's death in April 1945, Truman, after only 82 days as VP, was thrust into the presidency. Utterly unprepared, he faced the collapse of Germany, a Europe in ruins, the organization of the UN, a summit with Stalin and Churchill, and the question of whether atomic bombs would be ready for use against Japan. Meanwhile, the Soviet Union was growing increasingly hostile towards US power. Truman inherited FDR's hope that peace could be maintained through cooperation with the Soviets, but he would soon learn that imitating his predecessor would lead only to missteps and controversy.

Spanning the years of transition, 1944 to 1948, Ascent to Power illuminates Truman's struggles to emerge as president in his own right. Yet, from a relatively unknown Missouri senator to the most powerful man on Earth, Truman's legacy transcends. With his come-from-behind campaign in the fall of 1948, his courageous civil rights advocacy, and his role in liberating millions from militarist governments and brutal occupations, Truman's decisions during these pivotal years changed the course of the world in ways so significant we live with them today.