Actually, I'm more inclined to think that the "ur-conspiracy theory" of US history would be that of the Anti-Masonic Party, an anti-Jacksonian party that appeared during the days of Andrew Jackson's Presidency. (The Anti-Masons started an enduring American political tradition, the national party convention.)
But the phrase is a catchy one. Kevin Baker used it in a 2000 essay, Another Day of Infamy: Congress is trying to legislate the history of what happened on the eve of Pearl Harbor.
The occasion of his column was a rider that some die-hard rightwingers in Congress had somehow managed to attach it to a defense bill that passed both Houses of Congress. It called for the poshumous restoration of their ranks to Admiral Husband Kimmel and General Walter Short. As Baker explains:
Kimmel and Short were, respectively, the Navy and Army commanders at Pearl Harbor at the time of the Japanese sneak attack there; they were demoted upon their subsequent forced retirements. Asking to restore their ranks is the most, legally, that our national legislature can do. The final decision will rest with the President. Congress would like him to exculpate both men, because they "were not provided necessary and critical intelligence ... that would have alerted them to prepare for the attack."
This last line is the rub. It passes the buck for the fiasco at Pearl Harbor to the high command in Washington at the time, most prominently President Franklin D. Roosevelt and Army Chief of Staff Gen. George C. Marshall. In so doing, it gives credence to the very ur-conspiracy theory of American history, the notion that Roosevelt or Marshall or both knew the Japanese attack was coming but deliberately kept the Pearl Harbor garrison in the dark, in order to maneuver America into World War II. (my emphasis)
His article is a good sketch of that particular whopper, which Roosevelt-haters latched onto as soon as they could find some half-credible reason to do so. The theory lives on, mostly among today's Old Right isolationists. Yet another reason that I'm always hesitant to cite their analyses of the Iraq War. And it seems that military history book clubsare always willing to promote yet another rehash of the tale.
A series of military and congressional investigations in the 1940s sought to answer this very question. Their general conclusions were the same as those of a 1995 Pentagon review, which determined that responsibility for the defense of Pearl Harbor that terrible day "should be broadly shared" but that "the intelligence available to Adm. Kimmel and Gen. Short was sufficient to justify a higher level of vigilance than they chose to maintain."
The vast majority of historians concur, and they are supported by the facts. There was plenty of infamy to go around for Pearl Harbor. The high command in Washington did blunder in not sharing every last scrap of information it had with Kimmel and Short. For that matter, even a garrison that knew the very moment of the Japanese attack would have had trouble resisting it, what with our unforgivable lack of preparedness more than two years after the rest of the world had marched off to war.
Yet Washington did pass on ample warnings that war might be imminent. ...
One is tempted to be flippant and ask, "Just what part of 'This dispatch is to be considered a war warning' didn't you understand?," but that would be unfair.
But not too unfair.
Baker's essay doesn't say who had sponsored the particular rider on which he focuses. But this article indicates that South Carolina's Dixicrat-Republican Senator Strom Thurmond, the inveterate racist who fathered a daughter with a black lover, was pushing this rehabilitation effort: A Special Report: Resurrecting the Kimmel Case by Fred Schultz Naval History Magazine July/Aug 1995.
This piece from Salon gives a quick look at the "ur-conspracy theory" on Pearl Harbor: Did FDR know? by Judith Greer 06/14/01
As she points out, it's a conspiracy theory that sometimes snares some leftwingers, as well. That makes them eccentric almost by definition. But the two examples she cites didn't need a Pearl Harbor conspiracy theory to give them that label:
The "FDR knew" conspiracy theory was revived again last week in a tendentious article in the New York Press by the left-wing contrarian Alexander Cockburn, who also revives the usual dishonest rhetorical habits of FDR's accusers. Cockburn cites, for example, a 1999 article in Naval History magazine that claims to "prove" FDR's prior knowledge by citing the fact that the Red Cross secretly ordered large quantities of medical supplies to be sent to the West Coast and shipped extra medical personnel to Hawaii before the attack.
These facts, like so many of those cited as proof of FDR's vile plot, can be explained quite readily without resort to the idea of a conspiracy. FDR had pledged to keep America out of foreign wars. At the same time, he was aware that our diplomatic efforts with the Japanese were only likely to buy us time, not permanently prevent war. No responsible leader could neglect the responsibility to be ready for any eventuality, but FDR also wouldn't have wanted the press to become aware of the necessary preparations. That would have been a political disaster and might have derailed his effort to quietly enhance our capabilities before war broke out.
Populist horsefly Gore Vidal, in the course of a book review in the Nation in September 1999, and again in a November 1999 (London) Times Literary Supplement article titled "The Greater the Lie," also lent credence to the "FDR knew" theory by praising - I can only assume without having read - the most notorious recent restatement of the theory, Robert B. Stinnett's book "Day of Deceit: The Truth About FDR and Pearl Harbor," first published in 1999 and new in paperback this month. (Vidal also presents the theory in his latest novel, "The Golden Age.")
Stinnett - whose previous historical work was a suck-up treatment of the elder George Bush's war years - purported to have new, recently declassified documents to support the idea that FDR was involved in a depraved political plot against our brave boys in uniform. But despite the book's surface appearance of being an earnest and meticulous investigation - complete with lengthy footnotes and reproductions of dozens of important-looking bits of paper - it's not hard for a careful reader to see the bilge water pouring out of it.
Incidentally, copious footnoting is a pervasive feature in what RichardHofstadter called the "highbrow" paranoid style. Conspiracy-mongers of the more literate variety are eager to show pseudo-scholarly support for their claims. Claims that normally, as in this case, don't hold up to any serious scrutiny. Greer continues her description of the Stinnett book:
It's not just that Stinnett's "evidence" - if it can be dignified as such - is at best ambiguous and circumstantial. It's not just that his theory, like most classic conspiracy theories, conflicts with reams of other available evidence and tries to make us believe two or more mutually exclusive things before breakfast. It's also not just that he - for all his apparently knowledgeable blather and the truckload of "documentation" he dumps on us - apparently doesn't understand some important realities of cryptology and signals intelligence. It's not even that it is impossible to believe that Roosevelt - who was, without a doubt, wily and subtle - might have perpetrated such a Machiavellian plot. No, the real reason to think there's no pony in this pile is Stinnett's relentlessly dishonest - dare I say "deceitful"? - characterizations of documents, incidents and testimony.
As with other such conspiracy books, "Day of Deceit" received reviews in responsible academic journals like Intelligence and National Security that demolished it, citing its nonexistent documentation, misdirection, ignorance, misstatements, wormy insinuations and outright falsehoods. The consensus among intelligence scholars was "pretty much absolute," CIA senior historian Donald Steury told me in an e-mail. Stinnett "concocted this theory pretty much from whole cloth. Those who have been able to check his alleged sources also are unanimous in their condemnation of his methodology. Basically, the author has made up his sources; when he does not make up the source, he lies about what the source says." In other words, even if Roosevelt were genuinely guilty of these charges, "Day of Deceit" couldn't possibly convict him.
This is also a good point about the FDR-planned-Pearl-Harbor kind of conspiracy theories:
One of the things that is most notable about the way the "FDR knew" theory is sustained is that its methodology parallels that of so-called creation science. The trick in both instances is to assiduously ignore all the mountains of evidence in favor of the theory you are trying to disprove and to focus instead on tiny apparent discrepancies and supposed "missing links" in the record. "True to the M.O. of all conspiracy theorists," [Stephen] Budiansky notes, "the ABSENCE of further documentary evidence actually confirms [the] thesis by proving that a'cover-up' has taken place." ...
The conspiracy theorists, in parallel with the creationists who maintain that God must have placed fossils in the ground to test his people's religious faith, also think that Roosevelt and his political allies managed not only to cover up their dastardly deeds but to fabricate thousands of linear feet of documents in order to camouflage the truth. It is perhaps remotely possible that some kind of massive effort of that kind was instituted here in America in the midst of wartime, but unless we want to believe that our former enemies have destroyed or manufactured material to burnish Roosevelt's reputation, evidence from Japanese archives also backs up the idea that the attack was a surprise to FDR.
Linda Goetz Holmes, for instance, a Pacific war historian with the Interagency Working Group at the National Archives and author of the book "Unjust Enrichment: How Japan's Companies Built Postwar Fortunes Using American POWs," told me about the findings of a Japanese historian whose research in his country's recently declassified files only became available in the U.S. in 1998. He revealed considerable documentary evidence of Japanese satisfaction with how well "our magnificent deception" was working in Washington. (my emphasis)
Sometimes I think that old conspiracy theories never fade away, they just keep being recycled with marginally altered packaging.