Welcome to the Heart of Portsmouth

In the heart of historic Portsmouth once stood a grand Georgian brick home—the Jacob Treadwell Mansion, built around 1765 by Charles and Mary Treadwell. With its elegant architectural details and commanding presence at Middle and Congress Streets, it wasn’t just a home, it was a civic landmark. Its halls welcomed figures like George Washington, Marquis de Lafayette, and the international delegates of the 1905 Portsmouth Peace Treaty.