I love the nails used in our house. We’ve probably thrown a lot away but I’m sure we still have hundreds left in the wood we saved.
Our nails, which are rectangular, look like the Type B cut nails, Circa 1810 – 1900 which fits in with when the house was made. I believe these were made by cutting a thin tapered slice from a steel plate. I presume they had a machine that could hammer the end of the nail to make the head.
Manufacture of these nails came about due to steel plate being widely available, again this ties in with the industrial revolution, which in the USA was roughly between 1760 and 1840.
We’ll keep a bunch as I feel they must have a use somewhere and I like how they look.