According to Max Brantley at the Arkansas Times:
It is the 50th anniversary of the incorporation of FedEx in Little Rock. Fed Ex now celebrates its anniversaries pegged to its move to Memphis in 1973, when it was lured in part by a promise of a Memphis airport expansion and $6 million loan. The rest is transportation history. Memphis is the logistics hub of the nation and has the second-busiest airport in the world. Governing magazine in 2010 called Memphis’ decision to lure the fledgling enterprise perhaps “the single most important economic development decision made in any major U.S. city in the past 30 years.” Which could also be said, in reverse, about Little Rock.
Actual operations didn’t start until after the move to Memphis.
Federal Express officially began operations on April 17, 1973, with 389 team members. That night, 14 small aircraft took off from Memphis and delivered 186 packages to 25 U.S. cities from Rochester, New York, to Miami, Florida. Though the company did not show a profit until July 1975, it soon became the premier carrier of high-priority goods in the marketplace and set the standard for the express shipping industry it established.