This is an infantryman's badge from the US Army, which show they are in the infantry. It is worn on one lapel, while another badge the same size that says US is mounted on the other lapel of the collar. It is made of brass. My husband wore one on his uniform in the 60's and I believe they are still used today, so they are not very old at all. I believe they date as far back as WWII, but I'm not exactly sure that is correct.