The first souvenir “post cards” were available for purchase in the United States at the 1893 World’s Columbian Exposition in Chicago. These cards featured illustrations of the various fair buildings printed on government-issued postal cards and privately printed souvenir cards. The government postal cards were imprinted with one-cent indicias while the privately printed souvenir cards required two-cents postage to be applied. Writing was not permitted on the address side of these cards.

Five years passed before private printers were granted, by an act of Congress on May 19, 1898, permission to print and sell postcards that bore the inscription Private Mailing Card. These cards could now be mailed at the same one-cent rate as the government-issued cards.

The federal government granted use of the word “Post Card” to private printers on December 24, 1901. Writing was still not permitted on the address side. Use of postcards with “divided backs,” allowing both the address and a message on one side, was permitted on March 1, 1907.

Besides depicting images of places that may no longer exist, postcards often contain messages offering documentation representative of a time and place. From observations of historic events to matters of personnel concern, insights are given into the life and times of the postcard's sender.