St. Lawrence Hall 1850 St. Lawrence Hall, one of the oldest public buildings in Toronto, was constructed following the Great Fire of 1849 that destroyed a large part of the city's core. Architect William Thomas designed the building in the Renaissance Revival style with Corinthian columns and a domed cupola. The entrance originally led to a shopping arcade connected to the St. Lawrence Market. The building had shops on the main floor and, on the upper floors, offices and a grand meeting hall used for social events and by prominent speakers, performers, and musicians. Abolitionist Frederick Douglass, Swedish soprano Jenny Lind, and showman P. T. Barnum all appeared in the hall, as did William Lyon Mackenzie, Toronto's first mayor and Upper Canada Rebellion leader. In the 20th century, St. Lawrence Hall lost prominence and fell into disrepair. By 1965, it was partially derelict and threatened with demolition. A campaign led by architect Eric Arthur resulted in the restoration of the building and its recognition as a National Historic Site in 1967.