The plainspoken man from Missouri who never expected to be president yet rose to become one of the greatest leaders of the twentieth century

In April 1945, after the death of Franklin Delano Roosevelt, the presidency fell to a former haberdasher and clubhouse politician from Independence, Missouri. Many believed he would be overmatched by the job, but Harry S. Truman would surprise them all.

Few chief executives have had so lasting an impact. Truman ushered America into the nuclear age, established the alliances and principles that would define the cold war and the...