There's no such thing as a "Union or Confederate" hem/dress/curtain/coat-tail weight. They've been in existence since at least the early-1800s and are still being manufactured (in the same shape) today. They were/are primarily manufactured for use in civilian clothing (mostly in Ladies' coa and dress-skirts) and in window curtains. A few have probably also been used in the coat-tail of military coats. That slim possibility does not make these weights we dig a "Union" or a "Confederate" hem-weight -- nearly all of them were used in civilian clothing and window curtains.