Basically all the US army records that are classified are top secret, secret and confidential. Obviously information that is assigned these labels will be determined on how damaging the information could be to national security.
This means that you’re not going to find information on how to build nuclear weapons and things of that nature, but there is a lot of information that is freely available to all US citizens by using your local records office and even the Freedom of Information Act.
What you’ll learn about US army records is that things aren’t always classified; the issue is with finding them. Every citizen has the right to know what their government is doing (within reason) and this is what keeps things available to you. The issue is that most of the older information from the army is in hard copy form and can only be found at the National Personnel Records Center. Over the last decade, most of that information has been put into a digital format that can be searched online.
You may be surprised that much of the US army records are not accessible through government websites. Since the information is considered public domain, there are many businesses that offer access to a database of the records that you can search for. These are for-profit businesses that will charge a small fee to use them. It’s completely reasonable amount like $15 to $30. This ensures that their servers run fast and the information is completely up to date. You can go through these records and check up on things you have of interest. Any news story that you have heard of government corruption have been found from these records, so the information is there. You just have to find it.
The interesting part about going through US army records this way is that it is much easier than going to the National Personnel Records Center. You can search for exact information, just like you can at any search engine. For the NPRC, you have to actually travel to the location and search through records on paper. Of course they’re going to have some sort of organizational aspect to it, but you won’t be able to search for a certain keyword and find every document you want. This is why accessing this information from a for-profit organization on the internet is far easier and saves you a lot of time.