The Colonial Advocate
This influential journal of radical reform was first published on May 18, 1824, at Queenston, by William Lyon Mackenzie. A native of Scotland, Mackenzie had immigrated to Upper Canada in 1820 and three years later settled here and opened a general store. Within a year he had established a printing office in his home on this site, but in November, 1824, moved to York (Toronto). Because of Mackenzie's frequent attacks on the "Family Compact", supporters of this group raided The Colonial Advocate's offices and damaged the press on June 8, 1826. The courts awarded Mackenzie damages and he soon resumed publication. Mackenzie severed his connection with the paper, now called The Advocate, in 1834, and the last issue appeared that November.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.