In 1874 Charles W. Stimpson and his wife, Loretta Fish Stimpson purchased the land on which the Thomaston Bank was located on Main Street and built a three-unit brick block with a shared west wall of the Union Block.

Charles operated a dry goods store in the west unit and the Thomaston National Bank occupied the eastern half of the block. The Honorable A. P. Gould, who lived in the Ranlett House on Main Street, occupied an office in the building as did the Post Office.