dec 7, 1941 - America join WWII
The US only joined the Second World war after the Japanese bombed Pearl Harbour. President Franklin Roosevelt worked hard to prepare Americans for a conflict that he regarded as inevitable. In November 1939, he persuaded Congress to repeal the arms embargo provisions of the neutrality law so that arms could be sold to France and Britain. After the fall of France in the spring of June 1940, he pushed for a major military buildup and began providing aid in the form of Lend-Lease to Britain, which now stood alone against the Axis powers. America, he declared, must become "the great arsenal of democracy." From then on, America's capacity to produce hundreds of thousands of tanks, airplanes, and ships for itself and its allies proved a crucial factor in Allied success, as did the fierce resistance of the Soviet Union, which had joined the war in June 1941 after being attacked by Germany. The brilliance of America's military leaders, including General Dwight D. Eisenhower, who planned and led the attack against the Nazis in Western Europe, and General Douglas MacArthur and Fleet Admiral Chester Nimitz, who led the Allied effort in the Pacific, also contributed to the Allied victory.
Added to timeline:
20th century US foreign policy