In 1846, President James Polk, driven by a belief in Manifest Destiny, waged a war to seize land from Mexico and expand the nation's boundary from Texas to California. But events could have plausibly gone very differently, resulting in a map of the U.S. that would be significantly unlike the one we have today.


When the war ended, the U.S. had acquired over 500,000 sq. miles of new land, including Texas and the Mexican territories that would eventually become the states of California, Arizona, New Mexico — and comprise significant parts of Colorado, Utah, Wyoming and Nevada.

But the conflict with Mexico had been controversial, as not everyone in the U.S. shared Polk's vision. The famed geographer and historian Donald Meinig — who, between 1986 and 2004, pubished a four-volume opus, The Shaping of America — contemplated how the U.S. would have looked if the war never occurred, producing a map (above) that he titled, "A Lesser United States."


As the award-winning historian Susan Schulten observes on her blog, Mapping the Nation: