Formed in September 1940, its purpose was to mobilise public opinion in America against joining the war against Nazi Germany in Europe, it fought to preserve traditional American non-entanglement in Europe's quarrels. The founder of America First was a graduate at Yale law school R. Douglas Stuart Jr, by consulting leading isolationists in Congress, and using family connections with prominent businessmen in Chicago, he drew together the diverse voices of non-intervention.
America Firsters were strong nationalists, and like many Americans they were suspicious of Europe, they were quite happy with the selling of arms to Britain on a “cash and carry” basis , but did not see Britain as an asset to American security, and Nazi Germany in their view was no threat to it. They believed America should build up its own military force primarily for national defence, in addition relying on their far distance from Europe as a protection, involvement in that area they further believed, would weaken American democracy.
As the European war gathered pace America First began to fight an uphill battle, it was hard to argue that the USA would be safer in the long run defending its own side of the Atlantic, than by keeping the war on the other side by supporting Britain and later the Soviet Union, especially when U-boats were already sinking ships close to American shores.
Adding to the problems of America First were the contradictory views of its members, its core was the anti-New deal Republicans, this conservatism sat poorly with liberals who had joined the movement mainly through fear that foreign involvement would wreck their domestic reform agenda. Though unwelcome to America First leadership, pro-Nazi and fascist organisations started to infiltrate local branches. One prominent America First speaker proved to be a German agent. The Anglophobia of many America Firsters was also a handicap at a time when much sympathy existed for the UK's plight.
Most damaging to the committee however, was the reputation it earned for anti-Semitism, as a result of Charles Lindbergh's speech at a America First meeting on 11 September 1941, when he expressed sympathy for the Jew hatred of Nazi Germany, he warned against agitating for war.
Despite its weaknesses and embarrassments America First fought on, but by the time of Pearl Harbour in December 1941, things began to turn against the isolationist bloc, its fight represented the last stand of American detachment from world politics, it was disbanded after Pearl Harbour.
Summing up, it is hard to see many strategic reasons for America going to war against Germany, until December 11 1941 when Hitler declared war on the U.S., even after Pearl Harbour a few days earlier, war against Germany did not seem desirable. Roosevelt's policy despite personal reservations was up-to Pearl Harbour, and probably until the German declaration of war, broadly isolationist. Some might even query why America got so heavily involved in the European theatre of operations after December 11 1941, and why they did not direct all their resources towards the war against Japan.