In 1821, Colonel Francis McLean built the first textile mill in what is now Rockville in partnership with George and Allyn Kellogg and Ralph Talcott, next to a spot known as "the Rock" with capital of $16,000. Francis McLean had partnered previously with some others in the Warburton Mill in Talcottville. "The Rock" was a natural dam of solid stone that made a high falls on the Hockanum River. In what is now the center of Rockville, he dammed up the Hockanum River and built a water-powered mill known as the "Rock Mill", which was possibly also known as the McLean Woolen Factory. By 1823 his mill was in full operation. The new mill was 80 by 30 feet, and its product was blue and blue-mix satinet. In 1826 power looms were introduced.
In 1821, Colonel Francis McLean built the first textile mill in what is now Rockville in partnership with George and Allyn Kellogg and Ralph. Talcott, next to a spot known as "the Rock" with capital of $16,000. Francis McLean had partnered previously with some others in the Warburton Mill in Talcottville. "The Rock" was a natural dam of solid stone that made a high falls on the Hockanum River. In what is now the center of Rockville, he dammed up the Hockanum River and built a water-powered mill known as the "Rock Mill", which was possibly also known as the McLean Woolen Factory By 1823 his mill was in full operation. The new mill was 80 by 30 feet, and its product was blue and blue-mix satinet. In 1826 power looms were introduced.