From a letter written by a Norwegian immigrant to friends back in Norway (November 29, 1851)
Imagine the sense of anticipation experienced by the early settlers as they waited for the blueberries to "come in." A pail full of blueberries must have been equivalent to a Doctor's prescription of a remedy for the winter doldrums. A cache of little blue pills enveloped in a flaky pastry crust or made into jam. Canning jars full of the cure, put away to enjoy later, knowing that later would come sooner than you think. It's a part of the fruitful abundance of a Minnesota summer. Blueberries.
I have family visiting and made a Blueberry pie, it's almost required at this time of year. All that is left is an empty pan.