This is a hard question that is open to discussion even among historians who specifically study World War 2 as a topic and specialize in it. 
The most frequent answers that would probably be given is: 
1. Pearl Harbor - with the attack of the Japanese on Pearl Harbor, USA was effectively dragged into the war which may have tipped the odds in favour of the Allies.
2. Stalingrad - the Soviet Union captured a huge German army in Stalingrad. The soldiers from this army were either imprisoned until the rest of the war or died due to hunger. In effect this meant that the German forces lost a whole army on the Eastern front. 
3. Normandy landings - the Normandy invasion gave the Allies a foothold on the beaches of Western Europe from where they could invade through the mainland right into Berlin by the end. 
        
             
        
        
        
D . All the above 
This is why he has been kept out of most history.
        
             
        
        
        
The answer to this question, is the Barons :D
        
             
        
        
        
Answer:
Franklin D. Roosevelt responded to the Great Depression with a series of economic measures collectively known as "The New Deal," which were designed to help bring the country out of recession, rejuvenate the economy and give the American people confidence in banking again.
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Answer:
The anti-Federalists and their opposition to ratifying the Constitution were a powerful force in the origin of the Bill of Rights to protect Amercians' civil liberties. The anti-Federalists were chiefly concerned with too much power invested in the national government at the expense of states. (Howard Chandler Christy's interpretation of the signing of the Constitution, painted in 1940.)
Explanation: