Are There Any 'Impossible' Series In US Coins?

OK, go buy the (single known) 1870-S Half Dime.

The first US coin series I though of was Large Cents. There is a term used in copper collecting, it is "nc" and is defined as not collectible. There are a few large cents that exist in such small quantity as to make them not collecdtible. Known examples are in museums or part of a known collection.

That said one might argue that because one or two of an item exists, there is always a chance that one will come to market. Museums rarely sell their unique coins, and if they ever did the bidding frenzy would truely be something to behold.

Your homework for the night is to research the recent sale of large cents from the Dan Brown collection. Make note of the nc coins involved and prices realized and the total the collection realized at auction. Extra credit for showing how many different collections were involved in dividing up that collection. Will the world ever see such a collection assembled in private hands again? Not likely. Please show your work.

How about the 1964-D Peace dollar?

I question whether certain coins really count as being part of the series. Things like the 1933 St. Gaudins, 1913 Libery Nickel, or the 1804 dollar were never intended for circulation (the 1913 Liberty wasn't even authorized to be made at all). So I think you could have a complete set of those series without having coins like that in the collection. Of course if I had the money and one of those was available I'd be thrilled to put them in my collection! I'm just saying you can legitimately call the collection complete without those coins.

Yes I know about this collection.
I did even order the catalogue although I do not specially collect large cents. The few I have are only part of my world coins collection.
He could even pretend his collection was complete as ANS borrowed the missing coin to him.

OK keeping it to just actually made for circulation the stopper is probably the large diameter capped bust half eagle. It's a short set, only made from 1813 to 1829. Ignoring varieties (So you don't need the 1828/7 with only 5 known, or the 1825/4 with only 2 known) there are only 13 coins in the set and every one of them was made for circulation. But you still need the 1815 and there are only 4 known ( RedBook says 4, Coinfacts lists 11, but it looks like so of the pedigrees may be questionable and it could be a few as 7. At least five appearances on the market in be last twenty years though.) Then there is the real stopper the 1822, only three known and two of those permanently impounded in the Smithsonian The other has been off the market for almost thirty years. I don't know who owns the third one. Bass didn't buy the Eliasberg coin when it sold in 82. But that is probably about the closest you're going to get to an impossible set.

It is pretty tough to come across an 1854-S Quarter Eagle unless your family just happens to have descended from a Chinese laborer who saved his first Gold Rush wage. It had a microscopic official mintage of 246 with around 10 known survivors.