Why did einstein write a letter to president roosevelt

He wrote the letter because the letter warned him that a single nuclear bomb would make a mass destruction. ... It was the fact that the Nazis had the ability to develop the atomic bomb. It could destroy the whole world. So he warned Franklin D Roosevelt in his letter

evaluate the extent to which the seven years' war (french and indian war, 1754–1763) marked a turning point in american relations with great britain, analyzing what changed and what stayed the same from the period before the war to the period after it.