Nobody has made real wrought iron, from scratch, in the USA since at least the 60's.
As far as I know, the last commercially produced wrought iron worldwide was a Swedish mill that was making wrought pipe for chemical plants, and they quit making it by 1974 or so.
There is, I believe, a company in Britain that is rerolling existing wrought iron-
http://www.realwroughtiron.com/
They do not actually "make" wrought iron, just reroll scrap they find into more commercially desirable sizes and quality levels.
In addition, there is a couple of companies in europe that make very low carbon steel, which forges quite nicely. Various european blacksmiths actually buy enough of it to keep them in business.
There was a company called tried importing this "pure iron" to the USA about ten years ago, but they went belly up.
Right now, The Wagner companies are importing some of it, however.
http://www.wagnercompanies.com/Pure_Iron.aspx
It is NOT wrought iron- real wrought is irregular, with silica inclusions of various sizes.
This Pure Iron is really steel, but a very low carbon content, very nice to forge steel. Imported, and only available mail order, it aint cheap, but a lot of smiths really like the way it forges. Angelo Bartolucci, who is an old school Italian blacksmith who has visited the US and demoed at Abana conferences and elsewhere, likes it a lot, and has done some pretty amazing hand forging with it.
Other than that, finding old scrap wrought is the only source. The quality varies a lot- bridges and other structures are the best- and price, and availability, are all over the map.