In 1775 the first post office was made. They used horse drawn wagons to deliver mail. Automobiles were first tested for mail collection in 1899; they were able to cover the same distance as a horse drawn wagon in less than half the time.
The first contract of mail collection by the automobile was for service in Baltimore in 1906. In 1911 "motor wagons" were used. In 1933 2% of mail collection vehicles were horse drawn. The post office vehicles were painted red,white and blue. Then they were painted vermillion red, but switched to red, green and black. And then they returned to red, white and blue for the color scheme. The vehicles went to the color white in 1979. In 1987 long lasting vehicles lighter and roomier than Jeeps were introduced.