You’re correct. 68,000 was the official US count in 1945.  140,000 is the usual estimate.  But the official Hiroshima list currently counts 269,446, including extra cancer deaths since the bomb, continuing to this day. WWII was already ending when the US used the unnecessary bombings of Hiroshima and Nagasaki to demonstrate its terrible new technology.  No other country has ever used nuclear weapons.