Marine Helicopter Squadron One (HMX-1) was established 1 December, 1947, at Marine Base Quantico, Virginia, as an experimental unit tasked with testing and evaluating military helicopters when rotary-wing flight was still in its infancy. Founded to test tactics, techniques, procedures, and equipment, HMX-1 has since become synonymous with helicopter transport of the president of the United States.

In 1957, rotary-wing movement of the president, vice president, and other important personnel originated when President Dwight D. Eisenhower, away on vacation, was urgently needed back at the White House. What would have been a two-hour motorcade trip was reduced to a seven-minute helicopter ride. On that day, HMX-1 earned its most prestigious of missions: direct support of the president.

Only Marine Corps officers with strict security clearances may apply to fly with HMX-1.

https://www.youtube.com/watch?v=-j5ob2dGmzI