sentences:  In 1943 the U.S. Post Office launched a series of thirteen stamps honoring the countries that had been overrun by the axis during World War II.Each stamp featured a full-color reproduction of one of the occupied nations.While the Bureau of Engraving and Printing had previously issued bi-colored stamps, it did not have equipment for printing the necessary multi-colored flag images; and so, contracted with the American Banknote Company to produce the stamps.