District Court-House and Gaol 1832
An Act of the legislature of Upper Canada in 1831 named Prince Edward County a separate judicial district. Land for a court-house in Picton was given by the Rev. William Macauley and construction began late in 1832. Two years later in this fine structure, built in the Greek Revival style, the first courts of quarter session of the new District were held. John A. Macdonald, later a "Father of Confederation" and Canada's first prime minister, practised in this court-room and successfully defended himself against an indictment for assault occasioned by a practical joke. Additions were made in 1861, but its main block is one of the province's oldest remaining public buildings.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.