If you have a full name, it may be possible on the pay sites FOLD3 and Ancestry, as these numbers may be found on departing/arriving ship's rosters, various unit/veterans documents, etc.

You must be thinking of the Brewster body shield 

this is the guy who designed it, Bashford Dean, he liked medieval armor

Next time I'm at Vicksburg I'll get some good pics of Battery B monument and their position markers

Beautiful badge. How's the 15th Corps badge and crossed cannons attached? Also, directly below the B Battery letter, it looks like something else may have hung from the badge. Maybe a ribbon behind the badge? Or simply decorative? Congratulations on a great find!

Hi everyone, I just bought a set of officer uniforms that may be from the Korean War. I tried searching online but couldn't find the person's name. Can anyone help me?

Is there a website for finding a WWI soldier's army serial number?

After some debate, I’m confident to say this is an elaborate (and expensive) wartime private purchase ID badge from an unknown jeweler.    Charles F. Jackson He was a residence Chicago, IL. Enlisted on 7/16/1861 as a private and mustered into "Battery B" Co. Illinois 1st Light Artillery. He was Mustered Out on 7/23/1864 at Springfield, IL. He would see fighting from Grant's earliest campaigns through Atlanta. He was a member of GAR Post # 5 (George H. Thomas) in Chicago, IL. He would pass away 4/27/1919.

I got lucky on a search.  Worthpoint describes it as "Vintage 51 US NAVY Nuclear Submarine Pride in Proficiency Brass Belt Buckle Rare".   #3914937665

Hopefully you can get more opinions, as I’m not 100% certain.