very rare and highly collectible original single-sided green and white porcelain enameled die cut steel directional sign manufactured for the independent subway system of new york city. the c. 1930's subway sign was likely framed in wood and mounted against the wall in or around a station. the independent subway system (ind or iss), formerly known as the independent cityowned subway system (icos) or the independent cityowned rapid transit railroad, was a rapid transit rail system in new york city that is now part of the new york city subway. it was first constructed as the "eighth avenue line" in manhattan in 1932. one of three rail networks that became part of the modern new york city subway, the ind was intended to be fully owned and operated by the municipal government, in contrast to the privately operated or jointly-funded interborough rapid transit company (irt) and brooklynmanhattan transit corporation (bmt) companies. it was merged with these two networks in 1940. the sign fabricator is not known. measures 52 1/4 x 22 inches.