Smith began his service with the U. S. Post Office on May 21, 1920. He would learn on his very first flight just how life-threatening delivering the mail could be. Flying through a fierce rain storm, the engine of his de Havilland DH-4 plane suddenly stalled. With acres of woodlands below, Smith managed somehow to maneuver his plane to the only clear strip of land around. Just as he was about to land safely though, his plane hit an unseen ridge. Smith's plane was crushed. The force of the crash threw Smith clear across the field.

Being an air mail pilot in the 1920s was a dangerous profession. One in six pilots died.

Fortunately, Smith landed in some brush and survived the crash with only minor injuries. In fact, Smith even continued on his route - delivering the air mail via train. In seven years of air mail service for the U. S. Post Office, Smith would have many such adventures. He would later write about these experiences in his book, "By the Seat of My Pants."

Smith's experiences typify the dangers which most air mail pilots faced. Without modern navigational aides, pilots needed to rely upon making visual contact with landmarks on the ground in order to make their way from city to city. When harsh weather made those landmarks impossible to see, a difficult job became near impossible. On average, one in six pilots died. But if anyone could dare to overcome such seemingly daunting odds, it was this group of young men. Many had been daredevils or barnstormers performing aerial stunts far more dangerous than delivering the mail. Others were fighter pilots during World War I.

The first few years of its existence, the air mail service faced mounting political pressure to prove its effectiveness. It scored a major victory when on February 23, 1921, Jack Knight completed the first overnight coast-to-coast delivery in less than 34 hours. The increased confidence in air mail led Congress to approve funding to build a network of light beacons and illuminated airfields across the country, enabling nighttime flying for the first time.

By the mid-1920s, the feasibility of air mail had been firmly established. Seeking to shift air mail service to the private sector, Congress passed the Kelly Act in 1925. The legislation enabled the government to hire private carriers to deliver the mail. The government contracts that were subsequently awarded helped determine which airlines, including United Airlines, American Airlines, TWA and Eastern, would come to dominate commercial aviation over the next several decades. By the end of 1927, the U. S. Post Office ended its responsibility for flying the mail. Most air mail pilots, like Dean Smith, moved on to work for commercial airlines.