In the middle of the Sonoran Desert, two eagles meet face to face.

One has flown from the north, the other from the south. After a long journey, they confront each other in a vast territory that unites two great countries that, like the eagles, are not as different as they seem. Two hundred years after the beginning of diplomatic relations between Mexico and the United States, Ricardo Sheffield takes a look at the shared history of both nations.

He considers questions such as: What was life like for the Native Americans? When did some decide to follow an unknown path south, leaving others to stay behind? What unites the lives of Mexicans with those living in the United States of America? What have been the moments of greatest tension between the two countries?

With a distinctive voice full of irony, humor, and popular sayings, the author traces the history of these two great powers—from their common beginnings with the Clovis culture hunting mammoths to the civil wars of both countries, the promulgation of their respective constitutions, and their struggles to abolish slavery.