Gateways, inland seas, or boundary waters? Historical conceptions of the Great Lakes and the St. Lawrence River since the 19th century

Key Messages Since the late 19th century, historians, geographers, and other scholars have conceived of the St. Lawrence River as a gateway that provided the basis for an east-west transcontinental nation. Although the Great Lakes initially were incorporated into the national histories of the United States and Canada, increasingly they came to represent boundary waters that transcended political borders. Environmental issues encouraged a few writers to think more about how the Great Lakes and St. Lawrence might be thought about together, as sharing waters and a history.