He was the father of James Fenimore Cooper, who became a noted writer of historical novels related to the New York frontier.

By the end of the decade, he was a successful land speculator and wealthy frontier developer in what is now Otsego County, New York.

Soon after the conclusion of the Revolutionary War, he acquired a tract of land several thousand acres in extent within the borders of New York state and lying along the head waters of the Susquehanna River at Otsego Lake.

The judge and other investors also founded De Kalb, New York, near the east end of Lake Ontario and the St. Lawrence River, in 1803, platting approximately 64,000 acres and selling the parcels on.

The existing De Kalb Historical Society building was built by the judge's nephew, William, and some of his descendants may still live in the area.

[2] In 1796, Cooper determined to make his home permanently in the town he had founded, which by that time promised to become a thriving settlement.

In the first decade of the 1800s, Cooperstown began to struggle financially and saw a significant increase in violent crime, with Cooper himself being caned in the streets in 1807.