A website for factory tours was shared with me via e-mail by my local homeschool group recently. It lists some of the many factory tours in the United States. A lot of those in Wisconsin are for microbreweries, predictably, but there are also tours of cheese factories and historic architectural places like the Johnson Wax buildings.
If you travel after the public schools are in session as we do, I thought you might find this factory tour site useful for getting the most out of your time on the road. You might also find it a nice resource for planning low-cost or free road trips and educational outings at any time of the year. Begonia