On this day in economic and financial history...

One of the largest corporations in the world was created by legislation on Feb. 20, 1792, when President George Washington signed the Postal Service Act into law. Although it had existed in an early form for the rebellious American colonies since the Continental Congress appointed Benjamin Franklin postmaster general in 1775, it was only with the 1792 legislation that the basic legal and operational framework of the U.S. Post Office came to be. That year, the fledgling nation created 75 regional post offices and operated 2,400 miles of service routes, delivering letters at a rather high cost of $0.06 to $0.12 apiece.

The Post Office grew rapidly. By the turn of the 19th century it had established a total 903 branches on an operating budget of $214,000, which works out to about $2.8 billion today. Thanks to efficient operation, the Post Office turned a sizable profit, which became difficult as it expanded to handle the needs of a fast-growing, far-flung nation. In 1971, in an effort to reduce the costs of government, President Richard Nixon signed the Postal Reorganization Act, which transformed the U.S. Post Office into an independent for-profit entity, the United States Postal Service.

In 2011, the USPS generated $66 billion in revenue by handling 167.9 billion pieces of mail, which works out to about 40% of the entire global mail volume. The USPS also shipped more than 148 million Priority Mail Flat Rate boxes and more than 42 million other packages that year. To get all this mail to its destination, the USPS employs 546,000 people in career positions and uses 213,881 vehicles -- the largest fleet in the world. By comparison, UPS (UPS 0.02%) generated $54.1 billion in revenue in 2012, delivering 4.1 billion packages and documents with the aid of 397,100 employees using 96,394 vehicles. FedEx (FDX 1.37%) has a similar operational breakdown, generating $42.7 billion in 2012 revenue by delivering roughly 3.3 billion shipments with the aid of more than 300,000 employees using more than 90,000 vehicles.

Party like it's 1899
On Feb. 20, 1899, the 2-year-old Dow Jones Industrial Average (^DJI 0.56%) made one of its strongest advances to that point in time, rising 5.8% on high volume as a merger-driven bull market shifted into high gear. Railroad shares, which drove broader market gains throughout this bull market, offered mixed performance on the day, but the commodity-laden Dow was propelled upward by American Sugar and American Tobacco, the latter of which posted a double-digit price gain. More than a million shares exchanged hands -- a rare event in an era before telephones were widely used.

American Tobacco, popularly known as the "Tobacco Trust," is the parent of three of the four largest tobacco companies in the United States. It was forcibly split into R.J. Reynolds (now Reynolds American), Lorillard, and Vector Group's Liggett & Myers in 1911 as a result of antitrust actions.

Why don't we have flying cars, anyway?
The first successful flying car was first noted in the press via a brief aside in a Los Angeles Times aviation column written on Feb. 20, 1937. A day later, Waldo Waterman's Arrowbile took off on its first successful test flight from Clover Field in Santa Monica. Powered by a Studebaker automobile engine and possessing detachable wings for road use, it boasted a top speed of roughly 60 miles on the ground and 120 in the air.

So why aren't flying cars commonplace? Ford (F 0.66%), which had been manufacturing aircraft as early as the 1920s, attempted to assess the market for a flying car after World War II but could not justify the additional regulatory hurdles necessary to make such a product successfully. Undaunted by Ford's abandonment of this project, two engineers attempted to create their own flying Ford car by attaching detachable Cessna wings to a Pinto. This Franken-craft worked about as well as you might think -- the two engineers died when the wings fell off in midair. But hope springs eternal: The International Flying Car Association, founded in 2012, eagerly touts the imminent emergence of two modern flying cars on the market. Both undertook successful test flights in 2012, but as we've seen, it takes a lot more than going airborne to move from cool sci-fi concept to legitimate consumer product.