A.J. Baime's narrative history focuses on Harry Truman's first 120 days as president, the most consequential four months any American president has faced. When FDR died on April 12, 1945, Truman had been vice president for just 82 days and had been excluded from almost all wartime planning. Within weeks, he faced decisions that would shape the rest of the century: the founding of the United Nations, the surrender of Nazi Germany, the liberation of concentration camps, the first use of atomic weapons, and the beginning of the Cold War with Stalin. Baime draws on diaries, letters, and contemporaneous accounts to recreate what it felt like to be thrust into such responsibility without preparation. Truman's background as a Kansas City haberdasher and machine politician seemed unlikely preparation for world leadership, yet he made decisions with a speed and confidence that surprised his advisors. The book captures the chaos of the final months of World War II, when events moved faster than anyone could fully comprehend. This is presidential history as thriller, focused on human beings navigating impossible circumstances.