Given sufficient time, and perhaps a map, most of us could name and locate all fifty of the current states of the union. This elegantly-round roster of half a hundred has been the stable stable since 1959, when after adding Alaska and Hawaii it's like we collectively decided that changing all the flags would just be too much work and quit adding any more states. Buy why? For most of American history, new states were the rule rather than the exception. The only thing that makes our geography inviolate is our own sense of permanence, however misplaced.
Trinklein's fun and illuminating book takes us on a tour of states that almost were (Franklin), never had a prayer (Montezuma), or could yet come to pass (Puerto Rico). Colonial ventures that never got off the ground, antebellum anti- or pro-slavery mapmakers' solutions, overseas adventurism, and modern power grabs. The history is fairly light lifting, essentially one breezy page per entry. It's the maps that make this book such a treasure for any geography buff.
You know, Texas and California could easily be broken up into multiple states. And probably should. Imagine adding Puerto Rico and DC and offsetting the Senate political balance by making Texas three states. Now you're getting into the fun.