Segmenting time, or periodization, is something we have to do if we want to organize the past and give it meaning. But it’s dangerous. By choosing some dominating event and saying that its period starts here and ends there, we run the risk of neglecting other events that don’t fit well into the scheme we’ve created, and that in turn risks distorting our view of how events have worked and built on each other to make the America we have come to know. Periodization matters. History is not the same, no matter how you slice it.

(cf.: West, Elliott. The Last Indian War: The Nez Perce Story (Pivotal Moments in American History) . Oxford University Press.)