As title states, ive been looking at a bunch of early coppers and keep seeing key dates that are counterstamped like the 1804 below. Why is that? also theyre always huge counterstamps to boot https://www.ebay.com/itm/1804-United-States-Draped-Bust-Large-Cent/114402238891?hash=item1aa2e7a1ab:g:dUwAAOSwJSlfWrpY
Well, the 1804 large cent is not really a key date. But the real answer to your question is that the people of the time that were using the coin as money did not consider it anything but a cent with which they could: 1) Buy something, 2) Advertise something, 3) Woo somebody, 4) Use it as a tool, 5) Or, just make a statement to posterity, like "Kilroy was here".
Dunno 'bout you, but *I* have always considered the 1804 large cent a key date. When I did a date set of holed pieces (the only way I could afford to even attempt a complete one-per-year set of large cents), the only ones I lacked were 1793, 1795, 1799, and 1804, as I recall. I totally agree with that summary, however, and it gave me a chuckle.
FWIW, I think counterstamps on old coppers are cool. Sure, I can understand how they'd be an obstacle to a mainstream collector, but they're chock full of history and character. I consider them "good damage", for the most part.
Hmm? Back in 1804, how many household goods were made of metal? Cooking pots? Plowshares? Knives? Axes? Rifles? I guess there weren't too many items that didn't have some utilitarian purpose. It wasn't like your husband or lover could dial up the local flower shop for a dozen roses.
It's not just key or semi-key dates. A large number of Large Cents are counter-stamped? Why? Money circulated and it was free advertising. There are a number of collectors in today's world that collect Counterstamped coins. By the way, dome of those counter stamps are rare.
Why? Well more than likely large cents were counterstamped indiscriminately. But as collecting took hold and damaged large cents were redeemed and returned to the Treasury, pieces that were recognized as rarer dates were NOT redeemed and over time the percentage of counterstamped rare dates as compared to common dates increased. If you had a handful of counterstamped large cents that were worth a cent apiece, but one of the was an 1804 the a collector would pay a couple dollars for even with the stamp, you held out the 1804 and scrapped the rest. So over time damaged key dates survived while damaged commons didn't.
Hm. Makes cents sense! Higher survival rate for the keys, due to collector activity. Large cents were likely among the earliest denominations to receive that collector attention, too, since people needed to spend the higher denominations to pay for stuff. A cent cost less to save, and it was an era when even a few cents still had buying power.
That explanation certainly is logical and satisfies the common sense criteria, but I would ask if the assumption in the OP's original post is correct. Is the actual survival rate of counterstamped, rare/key date large cents greater than that of their non-counterstamped sisters? I have never seen any evidence to support this contention but then I haven't ever seen any survival or population data on counterstamped coins of any kind. That could simply be because I don't follow or research the topic in any way and thus am ignorant (I'll never deny it).