On July 25, 1835 William Talcott and his son Thomas visited Mack, and at this time Mack announced his intentions to found a new community on the south bluff overlooking the confluence of the Rock and Pecatonica Rivers which he would name Pecatonic. Mack believed that the Rock River was navigable upstream for an additional 150 miles while the Pecatonica was navigable for 100 miles, and his site was ideal as a center for trade and commerce. The Talcott's returned to the East to get their families, and when they returned the following autumn, Mack had moved to the site of his new community, now located in the present day Macktown Forest Preserve.