Well, they were over 8 miles away when the bomb detonated, so they wouldn't have seen any of the destruction. Even reconnaissance planes were initially unable to survey the extent of the destruction due to the enormous amounts of smoke caused by the fires, and dust brought up by the bomb.
Also the service ceiling for the B-29 is 31,850ft. 40,000ft would've been impossible.
The invention of the printing press and improvements in literacy.
C. His plans for Reconstruction were not carried out
Answer:
The most important precedent was Washington's final act as president: He stepped down after completing two terms. Pressed to serve a third, he believed that a peaceful transition of power to a newly elected president would be in the nation's best interest.