What is illegal if the US Treasury Department prints the currency?
Odd serial numbers
Which of these Freezes Solid species thaws in winter and spring?
Answer: Living Persons
Even if it's just a matter of national pride It seems to be a design aesthetic that all US currencies with a person portrayed on them bear the portrait of a long-dead but historically significant American, both national pride and a legal issue. Under the laws governing the production and printing of US securities (including currencies), it is forbidden to present a portrait of a live person on securities. Therefore, the US Treasury Department maintains the policy of selecting significant figures from American history that are well known to the public. The current portraits were originally selected in 1928 and updated several times with the introduction of new security features and layouts.
Although this is an interesting treat, the decision to ban living humans has marked an even more interesting history of being marked on currency. The law dates back to 1866 and came about when Spencer M. Clark, the then National Superintendent of the National Currency Bureau, had issued a 5-cent paper note that showed his face. Not only was this generally considered distasteful, but because of his various scandals involving him, Clark was not particularly popular with the government. Shortly after the release of the scandalous 5 cent mark, the next bill was changed