Pres. Harry S. Trumman.
If you are referring to WW2, then the US stopped using atomic bombs on Japan because Japan agreed to surrender. Had they not, the US had plans and production setup to drop a total of 23 atomic bombs on Japan in 1945.
roseuavelt
President Harry Truman
Truman
Harry S. Truman
President Truman
Harry Truman authorized the use of atomic bombs against Japan.
President Truman got the order to use them against Japan.
Drop atomic bombs on Japan while they were in WWII.
There were no more atomic bombs to drop. Further, the Japanese government had already sued for peace.
The atomic bombs were delivered by the USS Indianoppolis
President Truman.