A "Los Angeles Gazette" dummy headline reads "JAPS BOMB PEARL HARBOR, 2 U.S. Warships, 2 Jap Air Carriers Reported Hit." Obviously many more American ships were hit, and no Japanese ships were damaged during the attack.
In the opening scene, one of the angels remarks to the other about mankind exploding itself; that the atom bomb will "...blow the earth sky high". The earth and sky are one entity. If the earth explodes it will blow up into space.
The Devil talks of the Salem Witch Trials, and the hangings and burnings. But NO ONE was burned as a result of the Salem Witch Trials. The executions were carried out via hanging only, while others died during efforts to extort confessions of being a witch.
The movie has Hitler saying "Today, I invade France. This is my last territorial demand." Though Germany claimed Alsace-Lorraine (and was annexed after France was invaded), it was never a demand of Hitler. Hitler was actually looking east (The Soviet Union) for territorial expansion. Germany only invaded the west in order to secure his rear when he did invade the Soviet Union. Further, as he never claimed French territory, he could not state that that would be his last territorial demand.
The movie has Hitler saying "Today, I invade Russia. This is my last territorial demand." After the war started in 1939, Hitler stopped claiming that this or that was his last territorial demand. Once the war started, he felt he was strong enough to extract what ever he wanted from his victims and no longer needed to justify his actions. Further, as he had never honored his word before, he knew no one would believe him again, so by the start of the war, he no longer felt the need to placate anyone by stating this was his last demand.
The Indians who sold Manhattan Island were dressed not as Eastern Woodland Indians did but as Indians of the Northern Planes (such as the Lakota, Cheyanne, Arapaho, Crow, or Blackfeet).
The cheap production values of this film produced anachronisms left and right. Some of the most obvious include: In ancient Greece, the hand of "Plato" is shown writing in cursive with a stylus, but he has no inkwell, and his shirtsleeve (on a toga?) looks more medieval or renaissance. In the next shot, "Aristotle" is surrounded by bubbling glass beakers filled with colored liquids, a la Frankenstein's laboratory. The "Indian" who sells Manhattan sits in front of a Plains tribe tepee and wears a full Western war bonnet.
Sir Isaac Newton published his famous paper outlining the law of gravity in 1666, but in the sequence in which Harpo Marx plays Newton he performs on the harp Stephen Foster's song "Beautiful Dreamer," written in 1864 -- almost two centuries later.
Elizabeth I is threatened by the Spanish ambassador with the Armada. The ambassador retires from the scene and Elizabeth rails against him and Spain. She summons Shakespeare who tells her of his new comedy "The Taming Of The Shrew." But the "Taming Of The Shrew" had yet to be written. The Spanish Armada was defeated in 1588, while "The Taming Of The Shrew" was written circa 1590-1592.
Groucho as Minuit sings the first line of Swanee River, which would not be written for another 200 years.