How did us policy change as the war in europe progressed 1939-1941

As the war in Europe progressed during 1939-1941, the US policy changed from neutrality to supplying essential military aid and other assistance to the allied nations to support them in the war.

Explanation:

The President of the U.S Franklin D. Roosevelt made it clear before the second world war that the U.S would not be taking part in any wars in any degree of involvement thereafter.

But as the Second World battle began, the United States began supplying essential military aid and other necessary assistance to its allies.

500 books can be produced by one man and a printing press within 5 months, while a copyist can only produce one in the same amount of time

a. because the u.s. was the leading with the most technology, economy, etc. also was teamed with other allies witch boosted the economy and materials to improve technology and use it.