First Nations knew that cranberries could prevent or cure scurvy, a condition which we now understand is caused by Vitamin C deficiency, and taught this medicinal use to settlers. Some First Nations also used it for bladder and kidney problems.
Cranberries have also always been popular as a food. First Nations dried them and mixed them with fat and/or dried meat or fish to make a portable "trail mix". In the early 1800s, settlers in Massachusetts began to grow cranberry commercially, making it one of the first native North American medicinal plants to be cultivated as a cash crop.
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