Because analyzing environmental problems implies being aware of interrelations and interconnections, historians should examine the interdependence of Latin American and US environmental history, rather than viewing them as separate fields. This article argues that an eco-political perspective on environmental history offers an interpretative framework that is useful for connecting the environmental history of the Americas as a continent. I illustrate this argument by analyzing two debates that connect both US and Latin American historical tradition and can be treated as a mix of environmental and political concerns: frontiers and imperialism. Environmental historians from the south and north of the continent are in a privileged position to establish common ground for research on a landscape with a shared colonial past and a controversial intertwined contemporary history. This article intends not to erase historical nuances and differences between countries of the Americas, but rather to shed light on the history of environmental transformation of our common Americas. My hope is that more US historians will discover that their US history is also Latin American history and vice versa.