Flying was a common way of travel after 1925.

Air Mail started in 1925.

The first commercial airlines included Pan American, Western Air Express and United Airlines.

United Airlines and American Airlines were the only two major airlines in the past.

The Federal Aviation Agency was responsible for determining airlines routes of travel and prices for passenger fares.

Before 1978, each airline couldn't offer lower fares to attract passengers.

The air traffic controllers strike in 1981 was due to the increase in air fares.

Some major airlines filed for bankruptcies after the Gulf War.

Many unfavourable factors had led the airline industry to a decrease in passengers during 2001 to 2006.