Vintage March for Victory pin. Made by the Ed Horn Co. in Philadelphia, PA. I have seen these listed as WWII and I originally thought it was. Upon further research, I have determined it is actually a pro Vietnam War piece. There is a five digit zip code on the side and zip codes weren't introduced until 1963.
Price is for one and we have several available. All are in good shape, but a few may have a small speck (see last photo).