Yes, US history books portray that the American atomic bombs ended the war. They ignore the Soviet declaration of war during the night before the dropping of the second atomic bomb.
The declaration of war was followed by the immediate collapse of Japanese forces in Manchuria, Korea, and Sakhalin Island in response to an invasion of more than a million Soviet troops. The declaration of war and invasion ended Japanese hopes that the Soviets would act as mediators to allow a negotiated settlement to the war.
The use of atomic weapons on Japanese cities may well have been more about preventing Soviet expansion into western Europe and Japan than about ending the war.