Noted historian Greg Grandin makes a broad historical sweep to define and understand the ‘frontier’ from key events like the American Revolution to the War of 1898 to the New Deal and finally the election of 2016. His contention is that America has been so busy over the last two centuries fighting wars and opening markets that this constant expansion served as a “gate of escape.” It helped deflect domestic political and economic conflicts and in effect allowed us to avoid confronting basic problems like racism and equality. These political passions that were deflected elsewhere for so many years have now come home to roost.