Cards with messages have been posted since the creation of postal services. The earliest known postcard was sent in London in 1840. The first American postcard is said to have been available in 1873, depicting the Interstate Industrial Exposition in Chicago. Later that year, the first “Postal Cards” were issued by the U.S. Post Office Department, featuring the bust of Liberty.  Postcards in both forms became popular as a result of the World Columbian Exposition in 1893, also held in Chicago. May of 1898 marked the start of the Golden Age of postcards in the U.S. when, through an Act of Congress, the same message privileges and rates were given to both types.