In the Coda of Frontier Country, Spero discusses some of the findings of the newspaper data-mining projects. Two key findings were that spikes in the appearance of frontiers coincided with war and that most colonial Americans were aware of frontiers throughout the Atlantic, not just their local ones. Spero discusses how this global awareness of frontiers throughout the Atlantic World helped British colonists imagine their place in an expansive British Empire. He then shows how the American Revolution severed this connection and, in turn, shifted Americans focus on frontiers toward North American ones.
This series of maps, most of which use color and insets, could not be published in Frontier Country.