He explicitly named it "Now It Can Be Told." Only 17 years after the bombs, the whole book. The rationales for the target selection -- yes, it's straight from the horse's mouth, and plausible because it is directly not something somebody would just write to in any way "improve" his own reputation, I'd like to believe. He also wrote there something like, if I remember correctly, that his biggest worry during the last months of the war has been that the war could had been over before he gets to drop the bomb on some city with civilians which would provide for good demonstration. It's also obvious that the existence of "military targets" was totally irrelevant, except as a good excuse to be provided to the current president. Something which sounded like that to me, at least. Maybe somebody will locate the specific words. Also Groves, before the Senate, November 1945, about the suffering of the victims of the bombs:

"As I understand it from the doctors, it is a very pleasant way to die." (1)

Also see the book from my Edit 2, before.

1) https://www.atomicheritage.org/history/survivors-hiroshima-a...