Built in 1823 and in operation by 1828, the Belknap Mill is the nation’s oldest unaltered brick textile mill and was one of the first mills to convert from weaving to knitting during the Civil War. The original wooden mill burned in 1811 and was replaced by the brick mill that stands to this day, based on designs of a 1813 mill in Lowell, Massachusetts. It was listed in 1972 as one of the first buildings on the National Register of Historic Places.

In addition, the mill is operated as a community-focused museum and cultural center, featuring knitting machinery that still operates, the 1918 hydroelectric power generating system, rotating historical and art exhibits, and concert and lecture series.