Undivided Backs (Pre-1907)
Although postcards were produced as early as the mid-1800s (the exact date is still being debated), they were largely concentrated in large cities and used for advertising purposes. In 1898, private printers were first allowed to print and sell cards. These cards were inscribed with the words "Private Mailing Card" and had undivided backs. The backside of postcards with undivided backs was reserved solely for the address. The message was required to be written on the front of the card, next to the image. Therefore, as seen below, the image did not encompass the entire front of the card.
In 1901, private printers were finally allowed to use the word "Postcard." These undivided back postcards often featured real photographs. Kodak marketed the Folding Pocked Kodak camera in 1906 that allowed the public to snap black and white photos and have them printed directly onto a postcard. In 1907, the divided back postcard was finally permitted. During the era of the undivided back postcard, roughly 75% of all postcards sold in the United States were printed by European companies.