If this is Thursday it must be postcards, 454

 Antebellum homes, New Orleans, Louisana, ca 1970s

This Grant L. Robertson photograph on an unused postcard from the 1970s has examples of cast-iron work on two balconies and found throughout the French Quarter in New Orleans, Louisiana.  The card was published by the photographer in Metaire, Louisiana, and produced as a Mirro-Krome card by H.S. Crocker Co. Inc., of San Bruno, California. It has GLR-C-455 as the identifying code at the upper middle on the reverse. 

The buildings, found in New Orleans, Louisiana, and shown in the picture are described as antebellum homes.  The antebellum style was found from the American Revolution to the start of the American Civil War.  However, most are from approximately 1820 to 1860.  Plantation homes in the Deep South are also called antebellum although they look different from these and are mostly known for huge pillars and balconies that run along the entire outside edge of the house and create a shaded porch with a sitting area and not so much for the cast iron work. 

Founded by Jean-Baptiste Le Moyne  de Bienville in 1718, the French Quarter, also called The Quarter, Vieux Carré and Barrio Francés, is the oldest section in New Orleans.  It is one of the main tourist attractions in New Orleans.  Fortunately it is built on higher ground that other parts of the city, closer to higher and stronger levees on the Mississippi, and therefore suffered little damage during Hurricane Katrina in 2005. 

A blacksmith, using an anvil, forges wrought iron but cast iron is produced in a furnace and poured into molds.  After the iron cools the sand from the mold is cleaned off and the finished product is ready to be used as decorative railings, banisters, balconies, garden furniture and even plates for stoves.  Also since more manual labor was needed for wrought iron items, cast iron would have been less expensive.  

In the photograph one balcony has been left "natural" or painted black while the second one is painted white.  Both have a lace-like quality and are typical of the homes found in this area.  The car in the foreground provides an approximation of the date.

For additional information, see:

https://en.wikipedia.org/wiki/Antebellum_architecture
https://en.wikipedia.org/wiki/French_Quarter
https://en.wikipedia.org/wiki/Ironwork