[jmecklenborg]

The airlines were deregulated by Carter in 1979. People who worship Ronald Reagan claim that Reagan deregulated the airlines but it was Carter. Look it up, flyboy.

Before that, the major airlines were required to provide direct domestic flights to all cities of a particular size. This meant there would always be at least one daily non-stop between, say, San Antonio and Columbus, OH and between Portland, OR and Memphis. After deregulation, the various airlines all reconfigured their service around hub and spoke systems. The airlines that could not establish a midwest hub in Chicago or Atlanta gave birth to the brief hubs that once lorded over various second-tier airports. The most notorious was Delta's Cincinnati hub, which saw everything that would have come through Chicago instead routed through CVG. This made no difference for connecting travelers but it enabled Delta to price gouge Cincinnati's customers since there was practically no competing airline at the airport. Then when Delta suddenly pulled out in 2005 all of the businesses (especially the Japanese businesses like Toyota) that had established major offices in Cincinnati in the 80s and 90s started to leave.

St. Louis, Pittsburgh, Charlotte, etc. all went through this routine with various airlines, many of them now defunct. The airports were expanded for these hubs then the airlines skipped town and left those cities holding the bag. Cincinnati is down from 500+ daily flights including about 10 internationals to maybe 150 daily flights and just one Air France flight to Paris which remains so that GE Aviation can trade spare parts and specialized personnel with Airbus. Luckily, the huge excess capacity at CVG lured DHL to the airport and they operate a 1,000+ man operation there that sees several dozen domestic flights converge at nightfall. Everything is sorted and then shipped either to Frankfurt or Hong Kong.