Just looked up your post about that French chap in the photo with Mary Pickford. He'll almost certainly be a military attaché and as such you should be able to find out the names of those personnel as they were listed in most almanacs/gazettes of the day dealing with national data. Such appointments were high status, deemed socially important and as a consequence were publicly listed. Might take a small bit of digging but you should be able to find the name or names of those posted by the French government to the US in such capabilities (there probably won't be more than 1 to 3 people), after that you'll have to match faces from some other sources to names but that shouldn't be too difficult as military attachés were/are senior officers and often with some fame within their respective service. You're fellow is highly decorated judging by the campaign and award ribbons he's wearing as well which suggests he should have some legacy in the history books.I've about given up on the guy myself. But thanks for looking into it!