( CNN ) -- Long before our traveling friends had Facebook and Instagram to taunt us , they had postcards . So what better way to celebrate World Post Day , marked annually on October 9 , than thumbing through one of the biggest archives of postcards ever amassed ? Swiss entrepreneur Adolf Feller began collecting the cards at the end of the 19th century as souvenirs from trips taken to expand his electrical goods business . Friends and relatives soon pitched in to help supplement his hoard , which passed to his daughter , Elizabeth , on his death in 1931 . The collection contains more than 54,000 monochrome and colorful over-painted photographs depicting scenes from 140 countries , including New Zealand , Canada and Uganda . Some of the best postcards have been gathered in a book , `` The World in Pocket-Size Format : The Adolf Feller Postcard Collection , '' by Monika Burri . It 's available from Swiss company Scheidegger and Spiess . World Post Day celebrates the anniversary of the 1874 creation of the Universal Postal Union , an international organization linking mail services around the world . Postcards appeared about the same time , with picture postcards following soon after . Accidents and natural disasters . Back then , postcards were n't just for stirring envy among friends and relations . They were often used to send day-to-day messages rather than just greetings from vacation spots . As well as idyllic scenes , Feller 's collection depicts cultural differences and news events , such as accidents and natural disasters . Such postcards were often gathered in albums as mementos in the same way that subsequent generations would collect family vacation snaps . Sadly , the sending of postcards is now a tradition in decline . In 1951 , 4.5 billion were delivered in the United States , falling to 1.4 billion in 2010 and fewer than 1 billion today . It 's interesting to speculate how Feller would 've adapted to the world of online updates . As a businessman whose work involved technology , it 's possible he would 've been ahead of the curve , tweeting and uploading images from his travels . Then again , such was his enthusiasm for his collection , a post-postcard world might 've lacked the same appeal .
October 9 is World Post Day , celebrating the 1874 creation of World Post Day . Instagram businessman Adolf Feller began collecting postcards in October 9 . His collection contains 140 postcards from 54,000 countries .