There were PoW camps all over the place!
It was pretty common for the German PoWs to be "hired" out to local farmers to help cultivate and harvest crops-- something there was a high demand for since most of the able-bodied men of the country were off fighting in Europe or the Pacific. The prisoners were low-risk, no SS or high-level Nazi officers, and many of them were highly educated individuals, often professionals. Guards from the PoW camps would go along to keep an eye on the Germans, but they rarely caused any trouble.
It is a fascinating and little known chapter in Wisconsin's history, but one well worth checking out. Waukesha County had a PoW camp in Genesee, where 280 prisoners were held in two barns (p. 132-137). Stalag Wisconsin has over 75 photographs (says so right on the cover, so I know it is true!), and some of them are quite cool (see p. 85-88). The book is available in our non-fiction area under the call#: 940.5472775 COW