To add to the copyright conversation, assuming the work is covered under U.S. law [1] then wouldn't it be covered under the Copyright of 1909 law [2]? This law only granted copyright for 60 years, which means copyright would have expired no later than 2005.

[1] Because the photographer was a U.S. soldier. If he took some of those photos in other countries there may be other laws in effect. [2] https://en.wikipedia.org/wiki/Copyright_Act_of_1909