Postcards are a late 19th Century invention.
Originally they were intended as a less expensive alternative to letters, with little emphasis placed on a printed image.
Messages were written on the front while the reverse side was reserved for the address and postage only.
As postal regulations changed at the turn of the 20th Century, the postcards
quickly took the form as we know it today printed image on front and message, address and postage on back.
The United States Government first issued Postal Cards in the late 1870's.
These were pre-printed one-cent cards.
Privately printed advertising and souvenir cards cost two-cents to mail.
In 1898, the Private Mailing Card Act allowed private cards to be mailed at one-cent, but did not allow private printers to use the term "postcard" until
In 1902, Eastman Kodak introduced papers that allow photographers to print directly onto postcard stock.
The following year, Eastman Kodak introduced a camera just for taking postcard
This innovation allowed private individual to print their own photographic postcards.
In 1907, the United States authorized the use of divided back cards.
This allowed the sender to use the back side for both address and message, reserving
the front for printed images alone.
This is the beginning of the modern day postcard as we know it...
..and that is why there is such a large variety of original and antique post cards on the market.