As you may have noticed by reading other posts, Jessica, your chances of finding help here should be improved if you can provide more detail about him.
Some examples of questions you might be able to answer: Is Johnnie a given name, or a nickname? Does he have a middle name, or initial? Where was he from? If he is deceased, when did he die? When was he born? What was his branch of service (Army, Navy, Marine Corps, Army Air Force)
Also, it would no doubt be helpful if you could be more specific about what type of info you are seeking.