This document is a marriage contract for my 2nd great grandparents dated 1851 in Kentucky. As you can see both parties had to put up a 50 pound bond to insure the marriage took place. I was super surprised that they were still using British money as late as 1851.
Here is a link I found. Seems it was a bond. And not a payment. https://kentuckykindredgenealogy.com/2021/12/09/what-about-those-marriage-bonds/
No mystery. Settlers often used English Pounds. It was a matter of choice and County and Commonwealth affiliation. Money was not exchanged at all, unless the marriage did not occur. It was still a matter of conversion-the value of a U.S. $ to British Pounds at the time. No money really changed hands. Pounds were often used and used much later than 1851. I think you knew most of that, though. After all, your Grandmothers' father signed for a $100.00 Bond in 1890 in U.S. $, correct? Truth in editing: changed "Ponds" to "Pounds" in one appropriate location. I guess it is possible that Ponds were acceptable as a Bond...after all, it is Kentucky, so....
You'd be surprised.. Spanish reales were still circulating in the states around this time. They are truly special metal detecting finds, especially in areas like where I live that the Spanish never really came to.