As detailed by Read, Blake's genius must have been sparked by closely reading The Examiner as it promoted Louis Schiavonetti's engraving of Stothard's painting The Canterbury Pilgrims and Cromek's Chalcographic Society throughout 1810.
Blake's knowledge of the review of Dawe is almost certain since it appeared in the same issue in which the plan for the Chalcographic Society was published.
(19) With its focus on the Chalcographic Society, the Public Address was begun no earlier than the late spring of 1810, and I will suggest below that Blake likely worked on it through early 1811.
"The Context of Blake's "Public Address": Cromek and The Chalcographic Society." Philological Quarterly 60 (1981): 69-86.