The letters which were written bu Einstein to the President and to the United Nations was to warn them about the destruction that one nuclear bomb could do and about the ability of Nazis that they culd make an atom bomb.
<u>Explanation:</u>
The great scientist, Albert Einstein wrote two letters. One was a letter written to the President of the United States of America and the other one was written to the United Nations. The purpose of writing this letter was to warn the two of them about the destruction that one atom bomb could make and about the fact that the Nazis had the ability to make an atom bomb. It could destroy the whole world. So in his letter, he wanted to warn the President and the United Nations.
This letter led to the establishment of the Manhattan project. And as a result of this, by the summer of 1945, the United States of America had also built a nuclear bomb.
Answer: Here ya go :) I was falling behind and got impatient waiting for the dude to do it so I did it myself. I know it's been like 2 weeks but better late than never. Everything was rushed so sorry if it's not that nice and neat.