There are a bunch of papers online (and I've lost the URL, drabbit) that go into the establishment of the US currency after the US gained its independence. These papers have convinced me of several things:
1. All fantasy writers should do a stint as public servants, just for the understanding it gives of modern policy documents. It rather horrified me that I understood most of the papers because of my time in public sector policy rather than because of my time as an historian. I know bunches about coins and mints and economies and relative values and the invention of double entry book-keeping because of the historian side of me. I understood those papers, however, at a gut level because of my time as a public servant. I could decipher far too much about the writing contexts and personalities.
2. The history of Australian and the US owes a great deal to the history of the UK public sector. I knew this, but it has now been affirmed. We have these amazing cultures that are very literate and go back to our British foundations. This means there's a link between me and Richard Brinsley Sheridan and it's that both of us can perorate entertainingly on public issues at undue length. His undue length was much longer than mine, but then, he didn't have to compete with Twitter.
3. I ought to know why 1/90 of a dollar is a basic computing figure in the US in the late eighteenth century, but it escapes me and you would not believe how much this bugs me. It's something really obvious that I ought to know. (the US dollar as decimal was decided just after the papers I'm looking at, if that helps)
4. The early US government was filled with educated amateurs who had a great deal of intelligence and enthusiasm and applyed logic to some of the oddest situations.
5. That this paragraph is perfect in an unusual way:
"Twelve ounces of gold are coined into 44 1/2 English guineas, each weighing 5 dwts. 9 9/20 gr. The amount of 44 1/2 guineas is 207 60/90 ths. dollars; which sum being divided by 12 (the number of ounces of gold in 44 1/2 guineas) leaves a quotient of 17 55/180 ths. dollars, equal to the present standard price of gold,in Britain. But gold being worth 80/90 ths. of a dollar, per pennyweight, here; a guinea, if valued at 4 60/90 ths. dollars, should weigh only 5 dwts. 6 gr. At the same rate, a gold coin, whose current value, with us, would be 5 dollars, should weigh 5 dwts. 15 gr."
6. That my decision at age twenty not to specialise in economic history was a very wise one.