What about the Mason jar type of canning?

Mason jar not invented until 1858

No. There was a strange blade on an iron handle with a notch. You stabbed the tin and then levered the blade along tearing the tin along the edge of the top. They were in use when I was small in the early 60s. Nothing strange. It worked quite well but left jagged sharp metal.

They had this in the early 1800s?

They could have just axed for one.

^the only acceptable time to use "axe" instead of "ask". Bravo 👏🏽

Pocket knives used to have a short hook blade for opening up cans. I used it many times, very effective. Much simpler than a modern can opener. Now I'm wondering how far back in time those blades go. youtube.com/watch?v=m8jXwv… ..

And yet economists always assume a can opener.

Bc the impetus behind canning was military - Napeolon offered a reward, to feed his armies during march. Soldiers had bayonets to open tin cans. Only when they saw the domestic market of housewifes, was better opening method important.

My understanding is that canned goods were pretty unusual before the civil war. It was the war where soldiers developed a taste for them and took them back home. Also: pretty inconsistent and unsafe until Underwood’s Devillsd Ham crested the first successful brand (>1860s)