The forgery is laughable. This is how antisemites think Jews talk amongst themselves, but no one talks this way.
The memo starts off saying it is a record from the Central Conference of American Rabbis, but ends up claiming it is from the Central Committee of the Anti-Defamation League. The letter itself does not adhere to any normal business letter format - no date, no author, no signature, The Central Conference of American Rabbis meeting in 1937 was (rather famously) in Columbus, Ohio, not New York, and it was their 48th annual meeting, not the 47th. The 47th was in 1936 and held in Cape May, NJ. (And they always called them "meetings," not "conferences.")
So why is this ridiculous forgery in the National Archives? Because it is part of a multi-volume FBI file on the ADL.
Any crackpot can send whatever they want to the FBI, and the FBI policy is to save and index everything it receives. If an FBI agent sees a newspaper story or flyer or really anything he or she wants others to see, it gets indexed and filed. It even has a file on the Protocols of the Elders of Zion - but it doesn't mean that it validates the contents. It includes letters from concerned citizens asking if the FBI was aware of this secret plot by Jews to take over the world. Here is one of them, plus the FBI response with an internal addendum on the bottom.
The ADL itself forwarded some other antisemitic materials to the FBI if they felt it important. Sometimes entire books were sent and every page copied into the FBI archives. At times the FBI would obtain material and forward it onto specific field offices, or examine the material for clues as to who sent it.
So when someone requests materials under the Freedom of Information Act, the government sends literally everything that isn't classified - including the crackpot material.
