The Elegant Geographic Symmetry of America's Four Largest Cities

Looking at a map of the United States, have you ever noticed the spacing of America's four largest cities? The distribution on our four coasts, and even the ecological symmetry, is striking:

1. New York City is on the first coast -- the Atlantic -- in the forested northeast quadrant of the nation, east of the Appalachians.
2. Los Angeles is on the second coast -- the Pacific -- in the arid southwest quadrant of the nation, west of the Rockies and coastal ranges.
3. Houston is on the third coast -- the Gulf of Mexico -- in the south-central part of the nation between the crest of the Appalachians and the Rockies, west of the Mississippi River mouth and basin, in the ecological boundary between the forest and more arid lands.
4. Chicago is on the fourth coast -- the Great Lakes (so designated by the U.S. Coast Guard) -- in the north-central part of the nation between the crest of the Appalachians and Rockies, east of the Mississippi River source and basin, in the ecological boundary between the forest and more arid lands.

How did such remarkable spacing happen?

America's four largest cities -- New York, Los Angeles, Chicago, Houston -- are distributed in a striking way vis-a-vis our four coasts, two dominant mountain ranges, forest-prairie ecology, and the continent's greatest river.