The mill is in Dickinson Square which is even older than Canad itself. The mill was built out of limestone in 1860 by Moss Kent and his partner Joseph Currier. The mill as had a few different names it was first known as Long Island Flouring Mills, then Long Island Mills and also as Manotick Mills. It became known as Watson Mill in 1946. Currier sold his share and left in 1861 after the death of his wife. Dickinson continued to operate the mill till 1929 when it was sold to Alex Spratt. Alex died in 1935 but it continued to be run by the Spratt family until 1946. It was then purchased by Harry Watson whom gave it its present name. Harry had worked for the Spratts for most of their time at the mill. The mill was sold again in 1972 to the Rideau Valley Conservation Authority. They restored one run of millstones and machinary to the original condition it would of been in 1860, and it is still powered by the water turbine.

Some of the things that have been reported to happen at the mill are unexplainable noises and things being moved around, the main ghost known to haunt here is Ann Crosby, she was married to Joseph Currier for only a very short time before she died, she was twenty years old. She died following a tragic accident at the mill when her skirt got caught in a tubine ad she thrown violently against the wall. She died instantly.