Edgewater Mansion Back On The Market One of Cooperstown’s most historic mansions, Edgewater at One Lake St., is on the market for $2.7 million. The home, overlooking Otsego Lake, was built in 1810-12 for Isaac Cooper, son of village founder William Cooper and brother of James Fenimore Cooper. The home is currently owned by One Lake Street LLC, but previously was owned by the late Walter Rich, president of the Delaware Otsego Corp. The sale is being handled by…