The process of pressing molten glass by mechanical means was perfected in the United States between 1825 and 1826. The first press, a simple bench press for making furniture knobs, was probably developed by the New England Glass Company of Cambridge, Massachusetts.
It is not known who invented the full-size machine press but it also was probably developed at the New England Glass Company about 1827. It required two men to operate. One gathered and dropped molten glass into a heated mold. The second worker sheared the glass into the mold and then lowered the lever. This forced the plunger into the mold and pressed the glass into the pattern of the mold. The machine required easily trained labor, eliminating the expense of the costly, experienced head glassblower.
By the 1840s, improvements to the pressing machine and molds allowed glass to be mass-produced inexpensively. For the first time, the average American household could afford glassware to adorn the family table. Pressed glass continued well into the 20th century, and was made in a wide variety of patterns and forms. There were over 3000 different pressed glass patterns.