It is within the third period of bottle glass blowing in America that the industry arguably makes its greatest strides. Having endured the post-war Depression and successfully navigated through the troubled times of pre-tariff America, industrialists in general and Glass Houses in particular were primed for unprecedented growth and expansion by 1830. Optimism ran high as the country flourished, with industrialists taking full advantage of internal improvements and technological advancements enabling more efficient means of manufacture, unprecedented access to transportation and widely expanded markets. The Glass Industry was particularly well-aided by the creation and expansion of the rail system, the invention of the steam-driven paddle boats, continued growth of roads and canals and the resulting effect upon their ability to bring their products to markets previously unattainable. The inevitably occurring competition among Glass Houses drove owners and glassblowers alike to investigate new and more efficient manners of production, in turn reducing prices and increasing productivity. With lower prices came increasing public access to private molds, whereby small town "Doctors," mineral water manufacturers, and the like were afforded new opportunities to package their products within personalized, embossed bottles. Marketing their wares as part of a brand name, personalized bottles quickly became an integral part of any successful marketing campaign. And, with unprecedented population growth and generally widespread prosperity, the consumer culture was born and in turn, the Glass Industry was poised to make its greatest strides.
Most notable of the production changes in the "Expansion" period is the ever-increasing reliance upon full-sized molds, especially personalized private molds. Already on the wane in the previous period of bottle production, pattern molded flasks and bottles did not linger much past 1830, with bottles and flasks blown in piece molds supplanting them nationwide. And, though still used in some degree (especially in the production of large jars and demijohns), general usage of dip molds had ended by mid century, also a result of dependence upon full-sized molds. Other notable production changes include increased reliance upon specialized lipping tools and the more widespread use of artificial coloring agents as a means of marketing bottles and flask. In addition, the quality of the glass itself was improved as Glass Houses gained easier access to raw materials and continued to refine the process of creating the glass batch from which the bottles were blown.
Although not immediately noticeable,
each of the aforementioned changes steadily and inevitably separated
the once intimate relationship between the glassblower and his
work. No longer dependent simply upon the glassblower's skill
and artistry, bottles blown post-1830 bear gradually decreasing
evidence of hand-craftsmanship. With notable exceptions, artistry
is also lacking in the increasingly simplified flask designs of
the period, which by the 1860 have become somewhat lifeless and
generally uninspired. Still, figured flasks retained their popularity
throughout the period of expansion and they continued to be an
important product of most glass houses. And, in spite of their
gradual transformation from the complex to the simple, figured
flasks remained effective in celebrating popular styles, symbols
and notable political figures of the day.