Let's start with a disclaimer. I neither agree nor disagree with the sentiments expressed in this write up. It's here as a matter of record and the issues being dealt with, both at the formation of the America First Committee and how they might be compared to recent events, are far too complicated for my simple brain to comprehend. That being said...

The America First Committee was founded in September of 1940. It was easily the most powerful of the isolationist groups in the country before America's eventual involvement in WWII. At the height of its popularity, more than 800,000 members were involved in the "cause" to keep America neutral, the most noteworthy being Charles Lindbergh.

America First Committee Original Four Principles

1) The United States must build an impregnable defense for America
2) No foreign power, nor group of powers, can successfully attack a prepared America.
3) American democracy can be preserved only by keeping out of the European war.
4) "Aid short of war" weakens national defense at home and threatens to involve America in war abroad.

Proposed Activities of the America First Committee, September 5, 1940

1) To bring togethor all Americans, regardless of possible differences on other matters, who see eye to eye on these principles. (This does not include Nazis, Fascists, Communists, or members of other groups that place the interest of any other nation above those of our own country.)
2) To urge Americans to keep their heads amid rising hysteria of times of crisis.
3) To provide sane national leadership for the majority of American people who want to keep out of the European war.
4) To register this opinion with the President and with Congress

The America First Committee was dissolved four days after the Japanese attacked Pearl Harbor on December 7, 1941.