In February of 1920, the first transcontinental mail service flies from San Francisco to New York. The flight cuts almost three days off of the travel time of the railroads.
Four years after the mail system gets airborne, Albert Hegenberger and Lester Maitland fly from Oakland, California to Honolulu, Hawaii, successfully making the longest open-sea flight at the time.
On June 17, 1928, Amelia Earhart crossed the Atlantic, the first woman to do so.
In June of 1924, the ten millionth Ford Model T was sold. At that point there were other cars on the market that far surpassed the Model T in technology, but the feat was well deserving of celebration.
In 1927, the Model T stopped production. By this time, its price was only $290, 15 million of them had been sold, and personal modes of transport were commonplace among the middle class. Car dealerships began favoring flashier cars and tried to make as much money as possible.
While at first there were over four hundred burgeoning car brands, by 1929, 80% of distributed cars were Ford, General Motors, or Chrysler. The Great Depression picked off any brands that managed to survive the 1920s.