When President Harry S. Truman left office in January 1953, most Americans were glad to see him go. Since the introduction of presidential approval ratings, Truman’s 32 percent rating was the lowest for any departing president except for that of Richard Nixon, who 21 years later resigned amid the Watergate scandal.

Americans were tired of five consecutive Democratic presidential terms. The Depression and World War II were both over, and people wanted a different sort of leadership that could jump-start the economy.

The outsider Truman had been an accidental president to begin with. When an ailing President Franklin D. Roosevelt ran for an unprecedented fourth term in 1944, worried Democrat insiders panicked. They feared that far-left-wing Vice President Henry Wallace might end up president if Roosevelt died in office.

Party pros replaced Wallace with the obscure Truman, a Missouri senator. They assumed that if worse came to worst, the non-entity Truman would be a token caretaker president.

Earlier, Truman had been immersed in scandal, owing to his ties to corrupt Kansas City political boss Tom Pendergast.

When Truman took office after Roosevelt’s death in April 1945, he knew relatively nothing about the grand strategy of World War II. No one had told him anything about the ongoing atomic-bomb project.

But for the next seven-plus years, Truman shocked the country.

Over the objections of many in his cabinet, he ordered the dropping of two atomic bombs on Japan.

Over the objections of most of the State Department, he recognized the new state of Israel.

Over the objections of the Roosevelt holdovers, he broke with wartime ally the Soviet Union and crafted the foundations of Cold War Communist containment.

Over the objections of many in the Pentagon, he integrated the armed forces.

Over the objections of some of his advisers, he sent troops to the Korean Peninsula to save South Korea from North Korean invasion. ...