C. Douglas Dillon - heir to a vast investment banking fortune, and one of the richest men in America during his political career - was a Republican who served in a Democratic administration and became one of the greatest modern treasury secretaries. He believed in bipartisanship and public duty, a sensibility that has all but faded from the current political climate. With exclusive access to the family's archive, in The Dillon Era Richard Aldous sets fresh eyes on a well-documented period in recent American history, unfolding a deeply influential but somewhat overlooked political career. In 1953 President Eisenhower appointed Dillon as ambassador to Paris, and he promoted him to second in command in the State Department in 1958. Tapped by Presidents Kennedy and Johnson for treasury secretary to reassure Wall Street that the nation's finances were in safe hands, Dillon would become one of President Kennedy's closest advisors, and perhaps the only cabinet member who was a personal friend. His impact on the Kennedy and Johnson administrations was immense, not least in delivering the most comprehensive income tax cuts the nation had ever seen. Overseas he worked to sustain political cooperation as the Bretton Woods system threatened to unravel. By the time he left office in 1965, the Washington Post recognized Dillon as "by far the best Secretary of the Treasury of the postwar period," and European Economic Community president Walter Hallstein hailed a new "Dillon era." Dillon advocated for evolution and reform over radicalism, and he placed the national interest above party interest. The Dillon Era throws new light on the postwar period, identifying Dillon as a pivotal figure in American policymaking during these crucial years of the Cold War.