The Civil Aeronautics Act is signed into law, forming the Civil Aeronautics Authority in the United States.

The Air Commerce Act of 1926 created an Aeronautic Branch of the United States Department of Commerce. Its functions included testing and licensing of pilots, certification of aircraft and investigation of accidents.

In 1934, the Aeronautics Branch was renamed the Bureau of Air Commerce, to reflect the growing importance of commercial flying. It was subsequently divided into two authorities: the Civil Aeronautics Administration (CAA), concerned with air traffic control, and the Civil Aeronautics Board (CAB), concerned with safety regulations and accident investigation. Under the Federal Aviation Act of 1958, the CAA's powers were transferred to a new independent body, the Federal Aviation Administration (FAA). In the same year, the National Aeronautics and Space Administration (NASA) was created after the Soviet Union’s launch of the first artificial satellite.

The accident investigation powers of the CAB were transferred to the new National Transportation Safety Board in 1967, at the same time that the United States Department of Transportation was created.

In response to the attacks of September 11, 2001, the government launched the Transportation Security Administration with broad powers to protect air travel and other transportation modes against criminal activity.