Chris, 1879 was a warm year, so Captain Spicer was able to sail into the Foxe Basin further than he had in previous years, and there found a low lying piece of land that he named Spicer Island (why not, if you've got it, flaunt it

AFAIR, Captain Spicer claimed those island(s) for himself, not for the United States. it was a different age.) In following years, Foxe Basin was frozen in again all year. Finally when another ship got into the area, they didn't find the island, and people assumed Captain Spicer was hallucinating or drunk when he found the Spicer Islands, or had simply named a large ice floe.
And so the islands were not listed when Canada was made a Confederation in 1867, because they were not discovered yet. So they never belonged to the British Empire. Then the ownership of the islands were not enumerated whenever the US and Canada wrote & signed whatever treaties described the extent of their demesnes in any subsequent years because no one believed they existed. As the original post said, even today things are unsettled in the Arctic. And islands in the Eastern part of the north are of mixed ownership, usually Danish and Canadian, but there are even two tiny islands, St. Pierre and Miquelon, close to southern Newfoundland that still belong to France.
And that's how the situation was in the 1930's. Then in the early 1930's, a Canadian plane flew over the area and saw the islands (perhaps they were mapping the north); the newspaper didn't say. What to do! These islands of dubious ownership existed. The newspaper clipping said that at the behest of the US government, Mr. William C. Spicer Sr., my grandad, had ceded ownership of Spicer Island(s) to the Canadian government, and it said this was done in a formal document. I think I remember seeing part of the document itself, but I could be imagining things. If you're really interested, when I get back to Groton, I'll dust off my copy of the Spicer Genealogy where I found the article tucked in, and see if I can find exactly what it says.
For one thing, I don't remember whether Cap (my grandad) ceded ownership of all the islands known as the Spicer Islands, or whether he just ceded Spicer Island. There are certainly a North and South Spicer Island, and there are apparently more than were originally apparent (at least four little bitty ones). You can check this out if you Google Map North Spicer Island, Baffin, Nunavut, Canada. And I don't think the area Captain Spicer occupied for many years on Baffin Island, Akuliak (or Spicer's Harbor) was ceded to Canada formally. I believe Baffin had been covered in earlier treaties, but I'm thinking that since Captain Spicer wasn't one to do claiming for the US, perhaps a point could be stretched, and that he had a claim there, too.
So if the US government wants to claim ownership of bases in the Arctic, perhaps they should come to me (as the executrix of my Dad's estate, dad being Cap's only child, as Cap was executor of his dad's estate, and his dad was the person Captain John Spicer left his residual estate to, as he had no children), and I will happily sell them my personal rights to whatever it is we might own in the Arctic. For one thing, I don't remember whether Cap signed over mineral rights

Back in the 1930's this was all kind of a big joke in The New London Day, our local paper, which still exists BTW. I don't think those documents were loophole free.
That would be so cool! I could afford to go to skating competitions again.