According to “Pressed Glass 1825-1925” by The Corning Museum of Glass, the glass industry in the United States started with Britain’s depletion of natural resources, specifically, timber. It was proposed that raw materials be harvested and manufacturing be set up in the New World for import to England. A series of challenges led American glass factories to failure until 1825.
Glasshouses were mainly located on the eastern seaboard but demand on the Western frontier created an opportunity for success. Entrepreneurs set up shop in Pittsburgh in close proximity to the Allegheny, Monongahela, and Ohio Rivers forming the “Golden Triangle,” a natural highway system in which glass could flow through mountainous terrain. Soon after, glass manufacturing spread through West Virginia and Kentucky.
It was also during the 1820s that a more cost effective production technique of mechanically pressing glass into molds became widespread and made American glass competitive with European glass makers. Pressing started with a two men machine in which one dropped a hot glob into a heated metal mold and the other lowered a metal plunger forcing the glass blob into the mold and the corresponding pattern. Information was freely exchanged at the time. New variety and new forms soon emerged and could add a touch of whimsy to the dinner table.
“Carnival” glass is a pressed iridescent glass that became popular at the turn of the century and which Frederick Carder participated imitating the Art Nouvea style. Spray is applied while the glass is hot. It was often given away at carnivals. “Iridescent glass” was most popular from 1905 to 1920 and dwindled until 1930.
Semi-automatic blowing became fully automated in 1903 by Michael Owens and the process adapted to automatic pressing in 1916 by Corning Glass Works to produce Pyrex baking ware in which the heated glass went from the tanks directly to the pressing machine and straight to the annealer with almost no human interference.