Post Office Department issues first US postal card

May 12, 1873

Post Office Department issues first US postal card

Postmaster General John A. J. Creswell suggested the use of postal cards in 1870. Congress was slow to approve the request because of privacy issues. However, the first penny postal card was finally issued on May 12, 1873, in Springfield, Massachusetts.

http://about.usps.com/who-we-are/postal-history/postal-cards.pdf