Did the "America First Committee" accomplish what it was set up to do?
The goals of the America First Committee were partially achieved, but it is not clear that they were achieved because of the activities of that committee.
America First wanted to keep the US from getting involved in WWII. They were successful in this endeavor in that the US did not officially get into the war until after the Japanese attack on Pearl Harbor. However, the US did get more and more involved in an unofficial way through such things as the Lend-Lease Program and by escorting convoys through the North Atlantic. These were things the committee disapproved of. In that sense, the committee's goals were not achieved because the US got involved to some extent in the war. So, the committee's goals were partially achieved because the US did get involved in the war, but not in an official and total way.
But this does not mean that the committee itself "accomplished" this success. We cannot know for sure whether the committee actually had any impact on the decisions made by President Roosevelt. Therefore, if the committee had any impact, it was mixed at best.
The America First Committee (AFC) was established in September 1940. The America First National Committee included Robert E. Wood, John T. Flynn and Charles A. Lindbergh. Supporters of the organization included Burton K. Wheeler, Robert R. McCormick, Hugh Johnson, Robert LaFollette Jr., Amos Pinchot, Hamilton Fish, Harry Elmer Barnes and Gerald Nye.
The AFC soon became the most powerful isolationist group in the United States. The AFC had four main 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.
John T. Flynn played a major role in the organization's publicity campaigns. This included one advertisement that read: "The Last War Brought: Communism to Russia, Fascism to Italy, Nazism to Germany. What Will Another War Bring To America?"
In April 1941, Father Charles Coughlin endorsed the America First Committee in his journal, Social Justice. Although Coughlin was one of America's most popular political figures at the time, his open Anti-Semitism made his endorsement a mixed blessing.
Supporters of the America First Committee in the Senate attempted to defeat the administration's Lend Lease proposal. Gerald Nye, Burton K. Wheeler, Hugh Johnson, Robert LaFollette Jr., Henrik Shipstead, Homer T. Bone, James B. Clark, William Langer, and Arthur Capper, all voted against the measure but it was passed by 60 votes to 31.
In a speech in Des Moines, Iowa, Charles A. Lindbergh claimed that the "three most important groups who have been pressing this country toward war are the British, the Jewish and the Roosevelt administration". Soon afterwards Gerald Nye argued "that the Jewish people are a large factor in our movement toward war." These speeches resulted in some people claiming that the America First Committee was anti-Semitic.
The AFC influenced public opinion through publications and speeches and within a year the organization had 450 local chapters and over 800,000 members. The AFC was dissolved four days after the Japanese Air Force attacked Pearl Harbor on 7th December, 1941.