you can look up his rank (left arm) and see when he acquired that rank until he got further promoted.
You can get a general idea of where he was from the history of the 1st Infantry Division: 1st Infantry Division on Wikipedia Society of the 1st Infantry Division First Division Museum There are also quite a few books out there on the 1st Infantry Division. As for the above photo, my guess would be Sicily. Due to the mountainous terrain, donkeys were often used by the US Army in Italy during WWII. However, the 1st Infantry Division was also in North Africa which also had donkeys, so that cannot be ruled out.
