Before that date Duff had another business partner so it’s highly likely that the work can be dated between those two years.Plate numbers are especially useful in dating music.
This is about a much more important topic – dating printed music.
Unlike many other sorts of published works, sheet music can be produced rapidly in response to an event or public interest, and thus is a source of relatively unmediated and unrevised perspectives on quickly changing events and public attitudes.
Other documents in the collection include pre-Civil War travel passes for slaves, slave bills of sale, and plantation inventories.
What if there’s no watermark, or it’s inconclusive?
Well, there are a range of other things you can investigate.