The stamps and letters before you are American-mailed, but not U.S.P.S. approved. Nay, they were for an independent postal service called Hale and Co. Despite there being clear illegalities in setting up local posts, private citizens saw an opportunity to be had in delivering mail for cheaper prices that the Post Office Department of the time.
Hale and Co. produced the first postage stamps in the U.S. and were the first to offer them pre-cancelled and in booklets. When the book we're reading for L.W.A. Book Club this quarter, Neither Snow nor Rain: A History of the United States Postal Service by Devin Leonard, mentioned they had "octagonal stamps", I knew I had to give those a look. I like them a lot. I like them so much, I think I'll make a rubber stamp inspired by them. Who wants one?