I located inf. on your Uncle Benjamin A. Black on the WWiimemorial.com/registry Not alot of inf. but it does give his ID # 34637099 and branch of service US Army
What you can do is go to message # 2112 on this forum and request a copy of his IDPF (file) it takes about 6 months but well worth the wait. This file will tell you when and where he was killed etc.
Hope this helps
Do a search on this forum many people have given inf. on how you can get records from the goverment example National Archives you can search for your grandfather I.D. number and from there request his military records