Statement of Significance (as of designation - January 20, 1999):
From the late 1860s through the 1880s, the Harmony Mills Company was one of the largest American producers of cotton fabric for printed calicoes and fine cotton muslins. Harmony Mill No. 3 was the largest individual cotton factory in the world when it was completed in 1872, and was acknowledged as representing the state of the art at that time. The Harmony Mills district has been described as "one of the finest examples of a large-scale textile mill complex outside of New England.