A real Civil War corps badge. Commercially manufactured and privately purchased by soldiers.
Unfortunately, the vast majority of badges on the market today are fakes, peddled by a small number of sellers, though often with a cohort or two. Their sheer number has given them some credibility among the unwary, especially in online auction formats. It's a problem when the discreet and confidential mentoring that used to take place at shows has been replaced by the internet, where all information seems equal. It's the market for lemons, of course, where a marketpalce with asymmetric knowledge will be dominated by shysters and con-artists on the one side, and the eager and gullible on the other.