This is a list of glass factories that operated in Blackford County, Indiana, United States. Natural gas (and later crude oil) was discovered in Blackford County in 1887.[1] This discovery marked the start of Blackford County's participation in the Indiana Gas Boom. Manufacturers, especially glass makers, were lured to the area with promises of free gas, free land, and (in some cases) cash subsidies. Hartford City Glass Company, Sneath Glass Company, and Johnston Glass Company were the largest glass companies during the gas boom. The current Hartford Glass Company is the longest lived. During the 1890s, the Hartford City Glass Company was the third-largest window glass producer in the United States, and Sneath Glass Company was the country's largest producer of lantern globes.
During the early 1900s, gas supplies gradually became depleted—and the East Central Indiana Gas Boom gradually came to an end. Many factories closed or moved.[2] In the case of Hartford City's glass factories, the larger and better-managed factories (such as the large American Window Glass plant, Sneath Glass, and Johnston Glass) continued to operate, while the smaller glass works closed or were absorbed by other companies.