Tony in SC is correct that it is a Ladies footwear heelplate. Specifically, from a late-1800s Ladies high-top shoe. I do not know the technical name for the type of antique Ladies footwear shown in the photos below... Ladies "button-up shoe" maybe... but it has the exact type and size of brass heelplate (with a "cut-out" emblem) you found. The amazingly well preserved Ladies "button-up" shoe in the photo was excavated from an 1880s town dump in Colorado. Despite what you see sellers say on Ebay and Antiques Navigator, these heelplates are absolutely NOT from civil war soldier shoes or boots. The key clue is, the very small narrow heel would sink deep in muddy ground, which is why actual soldier boots & shoes have a large wide heel. These are definitely from Ladies shoes, not Mens.
Although a photo in the book "Relics Of The Coastal Empire" shows this type of heelplate as being civil war soldier heelplates, the book is incorrect. (The photo was posted here in the What-Is-It? forum as part of a previous discussion about the correct ID and POSTWAR TIME-PERIOD of these "cut-out emblem" heelplates.) I think the book's author is now aware of the error, but the incorrect ID in the book cannot be erased.
