I”m still pulling on this thread, but from what I have learned so far is that thread came on wooden spools beginning about 1820. These spools could be returned for a deposit and be refilled. Later in the 19th century this was discontinued, obviously no longer financially viable for the thread makers. Leading to a glut of empty spools that needed repurposing. Leading to all that terrific Edwardian and hobo spool art. I will let you know what else I find.