<P> The four - footed, free - standing U.S. Mail collection box was first suggested in 1894, following the successful use of such designs in Canada, and quickly became a fixture on U.S. city street corners . </P> <P> Unlike Canadian mailboxes, which were painted red, U.S. mail collection boxes were originally painted in red or green . Beginning in 1909, all mail collection boxes were painted a dark green to avoid confusion with emergency and fire equipment . Dark green gave way to olive drab green after World War I, when the U.S. Army donated a large supply of olive drab green paint to the Post Office . Olive drab green subsequently became the standard color for all U.S. mail collection boxes until 1955 . On 4 July 1955, Postmaster General Arthur Summerfield announced that the Post Office would begin painting all mail collection boxes in red, white, and blue to make them easily identifiable . Subsequently, the Post Office began painting mail collection boxes in red and blue, with white lettering . </P> <P> In 1971 the United States Postal Service changed mail collection boxes to the current USPS Dark Blue with contrasting lettering . The coming of the automobile also influenced U.S. mailbox design, and in the late 1930s, an extension chute or "snorkel" to drive - up curbside collection boxes was adopted . </P> <Ul> <Li> <P> USPS "Snorkel" collection boxes for drive - through access . </P> </Li> <Li> <P> A USPS collection box in Venice, Los Angeles in 2018 using the old olive green USPS coloring scheme formerly used between World War I and 1955 . </P> </Li> <Li> <P> Post box in Markham, Ontario, Canada </P> </Li> </Ul>

What are the blue boxes at the post office