Who is Winston Churchill?

I think you mean CHURCHILL.

Sir Winston Churchill was Prime Minister of the U.K. during WW2. For the first two years of the war, he led Britain as essentially the only country strongly resisting the Nazis. He formed a close bond with FDR, and made significant use of that political and personal friendship when the U.S. entered the war in December 1941.

There are dozens of excellent books about Churchill - just go to your local library and ask at the reference desk.

World War 2 started on 1 September 1939. Winston Churchill didn't become Prime Minister until 10 May 1940. Neville Chamberlain was his predecessor.