Late one night in 1970 in Independence, Missouri, I was working in the Harry S. Truman Library, helping Margaret Truman gather research material for her biography of her father. We had lunch and dinner with Mr. and Mrs. Truman every day, and after two weeks I had gotten to know them pretty well.

That night, after dinner, Mr. Truman began talking about the importance of a strong Presidency. He ticked off the Presidents he admired—Jefferson, Lincoln, FDR. “What did you think of Roosevelt personally?” I asked.

Mr. Truman paused. Then, weighing every word, he said: “Inside he was totally cold. He didn’t give a damn for you or me or anyone else in the entire world, as far as I could tell. But he was a great President. He brought this country into the twentieth century.”

I felt a swish—even a swat—of history’s wings.