The Delaware Military History organization may have some useful material, including pictures and camp activity reports and newsletters.

The National Archives and Record Administration (NARA) has basic records of German POW's held in the US. When the soldier was repatriated, their personnel record was given to the country for which they fought. Within that record might be what you're seeking.

As GenTracer notes:

[T]he roster lists remaining [in the United States] only show name and POW number.

 

I suggest that you write to his local military tribunal office (for his town of birth) to acquire his complete military record (with a gap from his capture to his repatriation). For each of the above, you'll need to send a letter of authorization along with a copy of your ID to show relationship.

 

To obtain personnel files for former German POWs, please write to: Deutsche Dienstelle (WASt)
Postfach 51 06 57
D-13400 Berlin
Germany

The Delaware Military History organization may have some useful material, including pictures and camp activity reports and newsletters.

The National Archives and Record Administration (NARA) has basic records of German POW's held in the US. When the soldier was repatriated, their personnel record was given to the country for which they fought. Within that record might be what you're seeking.

As GenTracer notes:

[T]he roster lists remaining [in the United States] only show name and POW number.

I suggest that you write to his local military tribunal office (for his town of birth) to acquire his complete military record (with a gap from his capture to his repatriation). For each of the above, you'll need to send a letter of authorization along with a copy of your ID to show relationship.

To obtain personnel files for former German POWs, please write to: Deutsche Dienstelle (WASt)
Postfach 51 06 57
D-13400 Berlin
Germany