The United States' Rise To A World Power After 1930 In the thirty years that passed between 1930 and 1960 a lot happened in America and Britain, making the first a new World Power while the latter saw its international influence diminished. The main reason for this was the Second World War. It left Britain in ruins, physically and economically. America, in stead, gained from the demand of war materials in Europe and at home. When Franklin D Roosevelt came into office in 1932 America, along with the rest of the world, was going through the worst crisis in history. Unemployment was sky high and the banking