False
Not all Americans shared this use of atomic weapons on Hiroshima and particularly Nagasaki.
Dwight Eisenhower was one who opposed it. He was privately reprimanded by his (then) boss, Henry Stimson (then) Secretary of War.
At the time of their use, all views on the Manhattan project (the development of atomic weapons) were completely unknown to the general public. People like Einstein knew and opposed it.
So not all Americans thought it necessary.
