The first two nuclear weapons dropped are very well known. But for a long time that was not the case. In fact, the appearance of these weapons was hidden from the public until late 1960, more than 15 years after they were dropped. As a consequence, there are a number of depictions of these bombs – magazine articles, movies and such – that show configurations that are fanciful and entirely dead wrong because the artists behind them had no idea what an atom bomb actually looked like.
But in late 1960 the Atomic Energy Commission (replaced in 1974 with the Nuclear Regulatory Commission… note that even the names denote a change from an organization meant to provide energy to one now devoted to regulation) finally released a pair of photos showing Fat Man and Little Boy. Since then far more information has been released, including the display of real but inert bomb casings in numerous museums.
This is how Aviation Week reported the reveal in the December 12, 1960 issue. Note that even then there was a distinct tinge of political correctness, a fear that showing photos of the bombs would hurt feelings. There’s also discussion of putting the Enola Gay on display at the Smithsonian, something that would not come to fruition for another four decades.