By the mid-1800s, glassmaking had split into three types: tableware, window glass, and bottles. Each type used different tools and workers, and each had its own union. Tableware workers joined the American Flint Glass Workers, window glass workers joined the Knights of Labor, and bottle makers joined the Glass Bottle Blowers. Factory owners focused on making just one kind of glass and knew that part of the business well.

Glass workers even helped elect socialist mayors and other city officials in Harrison and Monongalia counties in the 1910s. However, the 1917 Bolshevik Revolution in Russia sent the U.S. into a "red scare" that brought down the socialist movement and nearly the glass unions.

During the 1920s, some unions were on the verge of disappearing, but President Franklin D. Roosevelt’s New Deal helped bring them back. In West Virginia, glassmaking was a big industry, especially along the Ohio River, which had over half of the country’s glass factories. Skilled immigrants first formed strong unions, but as machines increasingly took over, unions weakened. New labor laws in the 1930s helped glass unions grow again, helping many of the 13,000 glass workers in the state.