Corrected entry: The show is set in a small town on the southern Minnesota prairie, which is flat and nearly treeless. But the show was filmed in the foothills of southern California in terrain which bears absolutely no resemblance to Minnesota. Certain episodes, for example, show the characters camping, fishing and hunting in mountainous terrain - there are no mountains within hundreds of miles of Minnesota.
Corrected entry: After Caroline starts working at the restaurant in town, who takes care of Grace? Charles is also working outside the home; Laura and Mary are teaching; Albert and Carrie, then later James and Cassandra, are at school. We don't see Caroline take Grace to anyone's home, nor does she take her to the restaurant.