Pro-Nazi German American Bund rally at Madison Square Garden. New York, United States, February 20, 1939. 
Fritz Kuhn, head of the antisemitic and pro-Nazi German American Bund, speaks at a rally. United States, between 1936 and 1939.
Cross posted from Radarsite
What exactly was the German American Bund?
The German American Bund, an organization of ethnic Germans living in the United States, was marked by a pro-Nazi stance. Aside from its admiration for Adolf Hitler and the achievements of Nazi Germany, the German American Bund program included antisemitism, strong anti-Communist sentiments, and the demand that the United States remain neutral in the approaching European conflict. Public opinion surveys of 1939 show that Fritz Kuhn, the leader of the German American Bund, was seen by the U.S. public as the leading antisemite in the country.
Actual membership figures for the German American Bund are not known with certainty, but reliable estimates place membership at 25,000 dues-paying members, including some 8,000 uniformed Sturmabteilungen (SA), more commonly known as Storm Troopers.
The German American Bund carried out active propaganda for its causes, published magazines and brochures, organized demonstrations, and maintained a number of youth camps run like Hitler Youth camps.
German American Bund activities often led to clashes--even street battles--with other groups, most notably with Jewish veterans of World War I. A February 1939 rally was held on George Washington's birthday to proclaim the rights of white gentiles, the "true patriots." This Madison Square Garden rally drew a crowd of 20,000 who consistently booed President Franklin D. Roosevelt and chanted the Nazi salutation "Heil Hitler."
The German American Bund closely cooperated with the "Christian Front" organized by the antisemitic priest Father Charles Coughlin. The activities of the German American Bund led both Jewish and non-Jewish congressional representatives to demand that it be investigated by the House Un-American Activities Committee chaired by Martin Dies. The Committee hearings, held in 1939, showed clear evidence of German American Bund ties to the Nazi government.
Shortly thereafter, Kuhn was convicted of embezzling funds from the organization and was sentenced to prison. In the following years, a number of other German American Bund leaders were interned as dangerous aliens, and others were jailed for various offenses. By 1941 the membership of the organization had waned. After the United States entered World War II in December 1941, the U.S. government outlawed the German American Bund.
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And what exactly is CAIR?