During the Middle Ages, warfare evolved rapidly in Europe. The materials used for building weapons, the type of weapons used and the role of the cavalry and infantry also changed significantly during this period. ... With the development of new weapons, new methods of defence were also created.
Passed on March 11, 1941, this act set up a system that would allow the United States to lend or lease war supplies to any nation deemed "vital to the defense of the United States."
