In his fascinating account of Harry Truman’s nomination to the Vice Presidency in the July/August issue (“‘I Hardly Know Truman’”), David McCullough refers to the secrecy that enshrouds Bob Hannegan’s half-hour visit with FDR aboard the presidential train on the eve of the 1944 Democratic convention in Chicago.

Over dinner one memorable evening several years ago the only other person present at that meeting described what took place. According to Grace Tully, FDR’s private secretary, when Hannegan, the Democratic party chairman, boarded the train, he bore a letter he had just received from Roosevelt.

As Tully recounts the story, the letter said, in effect: My preferences for Vice President are William O. Douglas and Harry S. Truman. Recognizing the implied preference for Douglas, Hannegan—who had not shown the letter to the convention—asked Roosevelt to have it rewritten, with Truman’s name listed first.

“You heard the man,” Tully says Roosevelt said to her. “Let’s rewrite the letter.” So, as Hannegan and Roosevelt looked on, Tully retyped the letter, the new version of which is presumably the letter reproduced in the McCullough article and which Hannegan then took to the convention. The rest, as they say, is history.

In a later conversation I pointed out to Tully that other accounts of the affair were at variance with her own. “The difference,” she replied with a quick smile, “is that I was there and they weren’t.”