Explanation

Franklin D. Roosevelt served as U.S. President from 1933 to 1945

He led the country through most of World War II.

During World War II, two atomic bombs over the Japanese cities 

• First Bomb, the Little Boy type of bomb was dropped in Hiroshima on 6 August 1945 
• Second bomb, the Fat Man type of bomb was dropped on Nagasaki on August 9, 1945

The Second World War was a global war

That started in 1939 and ended in 1945

Additional information:

Woodrow Wilson is the President during World War I

He served as the 28th president of the United States from 1913 to 1921.