Driving on one of the big suspension bridges across the St. Johns River in Jacksonville a few weeks ago, I could not help but compare it to the mere three seconds or so it takes to cross the Brickell Bridge in downtown Miami.
With the St. Johns, you know you are looking at a real river. Just to the south of downtown Jacksonville, it reaches a respectable width of about four miles.
The Jacksonville port, about two miles inland on the river, is impressive as well. It handles large amounts of bulk and containerized cargo and it is the second busiest vehicle handling port in the country, after New York.
Each year, over half a million cars - mostly Japanese - leave the port on trucks headed north, to Georgia, the Carolinas, Virginia, and other states.
Jacksonville has been an important port city in the country since the early 19th century - long before Miami appeared on the map.
It served as a commercial port and as a naval base. For a considerable time it was the southernmost port on the eastern seaboard, making Jacksonville the leading city in Florida. Prior to World War II, it was the biggest city in the state.
Today, metropolitan Miami is about twice the size of Jacksonville, but the Miami port never surpassed that of Jacksonville. The main reason - besides the fact that the Miami River is not navigable west of Le Jeune Road - is that Miami is 350 miles south of Jacksonville and a long way from those U.S. markets.
When it comes to airports, too, Jacksonville and Miami have very different orientations. And now Miami dwarfs Jacksonville. MIA handles more than seven times the number of passengers that pass through Jacksonville.
JIA has non-stop service to only 30 cities - all in the US - and there are only a handful of major airlines with regularly scheduled services. Notwithstanding its name, Jacksonville International Airport has almost exclusively a domestic function. In contrast, MIA is the largest in the world in terms of the number of airlines with scheduled services and it has non-stop services to 71 cities outside the United States.
The comparative histories of Jacksonville and Miami underscore a shift of Florida's center of gravity from the north to the south. They also illustrate a sharp geographic divide of the state.
During my trip, I picked up a Visitor Guide that contained a map of Jacksonville's geographic "reach." It shows the eastern half of the United States with concentric rings radiating from Jacksonville. It reaches, a bit overconfident perhaps, all the way to Canada. There is no question, however, that Jacksonville looks to the north.
South Florida, on the other hand, has in some ways disconnected from the continental United States and is more integrated in the regional economies of the Caribbean and South America. As Miami's airline connections indicate, Miami looks to the south.
Not so long ago, northern Floridians used to refer to their region as "South Georgia." Culturally, it is part of the Deep South. But if Jacksonville is the Deep South, where is Miami?
Well, here's what they think in Jacksonville:
Earlier this year, when the people of Jacksonville were polled about the Elian Gonzalez case - that was, quite literally, setting Miami on fire - they almost unanimously dismissed it as a "foreign affair." Don't expect to be able to get a cortadito anywhere when you visit Jacksonville.
Jan Nijman is a professor of geography at the University of Miami.