I agree that it is horsegear. I dug one very-very similar to it, about 30 years ago, near Fredericksburg VA. It was among some civil war bullets -- but as we (should) know, that doesn't reliably mean the item is from the civil war. I was told there's one on CS General Joseph E. Johnston's saddle in the Museum of the Confederacy ...but I've never seen that particular saddle, so I cannot solidly confirm the report.